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Introduction To Computer System

What is computer system .

In this introduction to computer system , we will discuss in detail what is a computer system, basics of computer, technical features of the computer system, computer hardware, computer software, computer system architecture and other important topics related to the Computer system. 

A computer system is defined as a digital electronic machine that can programmed to perform some operations as per the computer program instructions.

Introduction To Computer System Video Tutorial

The computer system consist of both hardware and the software components. The computer hardware components are the physical components mounted within the computer case and some are also connected externally.

The computer system needs to be directed to perform various user specified operations. And therefore , the computer system needs a program which directs the computer hardware. The computer program is also commonly referred to as software.

Computer System Block Diagram

The introduction to computer system includes computer system organization and architecture and its technical features.

In this computer introduction you will also learn hardware components such as mother board , hard disk drive ( Disk Memory ), power unit, Central Processing Unit ( CPU ) also referred to as micro-processor, Random Access Memory ( RAM ) , computer buses , cooling fans and other hardware components. 

Table Of Contents

What is computer .

• Features Of Computer System.
• Characteristics Of Computer.
• Components Of Computer.
• Functions Of Computer.
• Types Of Computer Systems.
• Computer. System Architecture.
• Computer. Block Diagram.
• Computer. Hardware.
• Computer. Software.
• Evolution Of Computer System.

Computer Definition

A  Computer system is defined as  a digital electronics  device  that  can  be programmed  to accept  some  inputs  in  terms of  data, then process  this  data as per the program instructions    and  provide  the  Output  in  the  desired  format  that can be used for some meaningful  work.

  The computer user interacts with the system using an application software and provides the input data. The data is processed by the computer system with the help of application software.

The application software in turn interacts with the operating system and the processed data ( or we can call program output ) is then sent to the output device.

It is the application software that provides the instructions to the processor CPU to operate on the data as per the program instructions and produce the desired output.

The output device could be either a monitor, speaker, printer, storage device or any other output device.

Features Of The Computer System

• Computer System Is Programmable.
• Computer Accepts Raw Data And Produces Information.
• Computer System Is A Digital Machine.

Computer System Is Programmable

The computer system consist of both software components and hardware components.  The hardware components are physical parts that we can touch and interact. Whereas, the software is essential to drive the hardware.

The computer program ( software ) is an essential component of every computer system which  directs the computer to performs various tasks.

The Computer system is  programmable. That  means,  the computer will perform the task only as per the program instructions.

The accuracy of the output depends upon the accuracy of the program instructions. The computer will produce wrong results if either input data or the program instructions are inaccurate. This is called garbage in and garbage out.

And therefore , the computer needs a program written in a programming language to execute a particular task on the computer system .

The Computer program directs the computer system through series of instructions. Each program instruction performs a specific part of the operation.

Functions Of Computer

Computers are now extensively used in every field we can possibly think of. Computers can handle simple tasks as well as highly complex tasks without any problem. Further, computer science is rapidly advancing both in terms of hardware and software.

A computer system is a complex combination of hardware and software that performs a multitude of functions. Computers can be programmed to handle everything from basic data processing to advanced applications across various domains.

It has become an integral part of modern life, impacting how we work, communicate, entertain, manufacture, and conduct research. In computer architecture , every computer performs four basic  functions necessary for computer to work and execute the program instructions.

Four Functions Of Computer

• Input Function.
• Processing Function.
• Output Function.
• Storage Function.

Applications Of Computer

• Data Processing: Computers can process vast amounts of data quickly and accurately. Computers can operate on data, perform calculations, sort information, and make decisions based on predefined algorithms.
• Storage: Computers can store data for immediate or long-term use. Computers are used to store and manage large volumes of data with the help of special software called Database Management System (DBMS). The DBMS can handle of types of data from text documents and images to software applications and multimedia files.
• Communication: Computers are essential for managing computer networks and communication, including email, messaging, video conferencing, and internet browsing.
• Multimedia: Computers are extensively used to create, edit, and play multimedia content, including audio, video, and images. Multimedia content is essential part of online education.
• Automation: Computers can control, manage and automate a wide range of processes, from industrial manufacturing, process management, to home appliances.
• Information Retrieval: They can access vast amounts of data, extract information and knowledge on the internet and retrieve specific data through search engines.
• Gaming: Computers are a popular platform for gaming, from simple browser games to virtual reality, 3D games with complex, graphics-intensive titles.
• Research and Analysis: R&D is essential part of development of modern technology and scientific research. They play a crucial role in scientific research, data analysis, and simulations for various fields.
• Creativity: Computers assist in graphic design, music composition, 3D modelling, and various creative endeavours.

What Is Computer Program ?

The software components are computer programs. The program consist of set of instructions that directs the computer system hardware components to perform the desired operations.

The computer programs are generally written using high level ( human readable ) programming language such as C , C++ , Java , Python and many more. 

However, a high level programs are first required to be converted into low level ( machine code ) machine instructions in the binary.   The machine instructions in binary at can be directly decoded and executed by the computer. This conversion is called program compilation.

The computer system interprets these program instructions and then performs the desired operations. The CPU executes the program instructions one by one.

The Computer Accepts Input And Provides Output

The computer converts raw data into information.

The Computer Systems are versatile machines and can be used to perform number of operations.  The data processing is one of most common application of the computer.

For example, a company   might use the  computer system for managing employee records stored into the database , customer database, inventory management, billing, record keeping, payroll processing, accounting and many such applications.

In order to use the computer system for any database operations, a DBMS   ( Database Management System ) software is required.

The computer system is also used to process the raw  data   and  produce the  information  that can be used for some meaningful purpose.

The processed data is called information. And the information  can be used for some meaningful  work  such as decision making within an organization.

Computer System Is A Digital Machine

The computer  is  a  digital  electronic   machine.  Which means, a computer  can understand  and  execute  instructions  on  in  binary  which consist  of  only two numbers that  is zero  0   and one  1 . The  binary  code  is also referred  as machine code  or machine language.

The computers central processing unit ( CPU ) is the brain of the computer system. The CPU is responsible to perform both arithmetical and logical operations.  

However , the computer’s micro-processor ( CPU ) can decode and execute instructions only in the machine code in Binary.

So, it doesn’t really matter  in which  programming language you  write the program code because  eventually,  all high level computer programs  must be first converted  into  low level machine code in binary . The machine instructions consist of only binary 0 and 1.  

And therefore, all programs in high level are converted into low level machine instructions that can be directly executed by the microprocessor. 

The conversion process to translate the high level program into low level machine code is called program compilation.

Why Computer Use Binary ?

Why computer understands binary 0 and 1 , characteristics of computer system.

The computers characteristics include automatic working, operating speed, accuracy of calculations, versatility, diligence, memory, program dependence and reliability of operational performance. 

• Automatic Working.
• Operating Speed.
• Accuracy Of Calculation.
• Computer Is Versatile.
• Computer Is Diligent.
• Computer Has Memory.
• Computer Needs Program.
• Computer Is Reliable.

Automatic Working

The computers are extensively being used for automatic operations. The computer once programmed to perform some task can continue without any human intervention.

The artificial intelligence has further enhanced this capability for the computers. The computer can repetitively perform many operations in the automatic mode.

Operating Speed

The modern computers are armed with the latest microprocessor can execute billions of instructions within a fraction of a second. That gives huge processing power to the computer.

And therefore, the computer can be effectively used for performing complex operations with very high operating speed.

Accuracy Of Calculations

The computer can perform millions of complex calculations and take the logical decisions as per the program instructions with remarkable accuracy.

However, the accuracy also depends upon the accuracy of the program instructions and the input data. The computer will produce wrong result if there are any mistakes into the program instructions.

This is often referred to as “Garbage In Garbage Out” ( GIGO ).

Computer Is Versatile

The computer is a truly versatile machine that can be used for many applications. The use of computer is now an essential part of every industry and profession we can possibly think of.

Apart from its applications in academics , the computers are everywhere. The computers are used by the students , teachers , musicians , doctors , engineers , accountants , police , armed forces and architects.

Both large scale and small scale companies are dependent upon the computers to manage their business operations.

Computer Is Reliable

The computers are the most reliable machines to perform multiple tasks without any mistake with the lightening speed.

And therefore , the computerized operations are the backbone of all top business corporations , global ecommerce giants such as Amazon , Reliance and for other companies.  

The computer system can also be programmed to enforce set of rules to ensure safety of the user and data security.

Computer Is Diligent

There are many business corporations and manufacturing companies that work day and night without any break. Such operations and production lines can be very well managed by the use of computers.

Depending upon the use, the computer hardware is specially tailor made to handle such prolonged operations.

Computer Has Memory

The computer system needs memory to store data and program instructions. The system memory consists of  both short term ( RAM ) and long term memory. The business corporations need to handle large volumes of data. The data needs to be stored into the permanent storage devices for the future use.

The computer system with front end application software , a database management system ( DBMS ) and the database is essential to manage such large volumes of data.

For example, tech giants like Google, Facebook handle large volumes of data related of the millions of users across the globe.

Computer Needs Program

The program dependence is another important characteristics of the computer. The computer is often said to be a dumb machine without any IQ. And therefore, the computer needs a set of instructions called a program.

A computer program is an essential component of every computer system. Each task and operation performed by the computer is completed as per the program. The program consists of set of instructions that directs the computer.

The computer is not going to perform any task on its own unless it is directed by the computer program .

Components Of Computer System

The Computer system consist of four basic components Or functional Units. In terms of functionality, the computer system can be grouped in to four units. 

The Computer System Components are :

• Input Devices ( Input Unit ) .
• CPU ( Central Processing Unit ) .
• System Memory ( Memory Unit ) .
• Output Devices ( Output Unit ) .

Input And Output Devises

Computer system input unit.

The term “Input Unit ” ( Input Devises )  refers to the  input  provided   by the  user  by  using   any   input  device  such  as  keyboard, mouse, mike, camera or any storage device in the form of input data.

The input data is operated and processed by the  Central Processing Unit ( CPU ) as per the program and sent to the output unit for further action.

Computer System Output Unit

The term “Output Unit ” refers to the  output  provided   by the   computer CPU after processing the user data inputs  .

This output is then sent to the output  device such as monitor , printer , speaker   to  provide desired  output to  the  user. The output can also be stored on any storage device for future use.

Computer System Memory Unit

The memory unit is an essential part of every computer system. The computer system needs memory to store the program instructions and the data before and after the processing.

The computer system memory unit consist of both temporary and permanent memory. The Random Access Memory ( RAM ) is the main memory where the operating loads the program for its execution.

The temporary memory RAM can store the data till the time the system is powered on . Whereas, the permanent memory ( disk memory ) can store the data even after the the system power is switched off. 

Memory Hierarchy

The computer  system  makes  the  use  of  different   types  of memories organized in a hierarchical manner  and together they are referred as memory unit. The arrangement of different types of memories is referred as memory hierarchy.

The computer memory unit consist of  different types of memories which  differ  in  capacity,  access speed,  physical  size  and  the  cost  of the memory. 

Primary Memory

Each  of  the memory   is  optimally  used  in the computer system  depending upon its  access  speed  , size  and  proximity  to the  CPU . 

The computer system makes use of different types memory depending upon the functional requirements .

The  computer memory  is  mainly  divided  in to  two types  based on the  data  retention  by the computer memory when  power  is  switched  off  to  the  computer system.

Computer Memory Unit

Computer System Memory

Temporary and permanent memory.

The computer memories can be grouped into  two basic types depending upon the data retention by memory when system power supply is switched off .

If the memory retains the data without power supply, then it is referred as permanent memory . For example hard disk , pen drive are permanent memory ( Also referred as secondary memory ) .

The Random Access Memory ( RAM )  is the main system memory for a computer system . The RAM is a temporary memory because it retains the data only till the time , the  system power supply is on.

The data in the RAM is lost once the  system is switched off . And therefore main memory RAM is referred as temporary memory ( also referred as primary memory ).

• Program Execution.
• Accept Data From Input Device.
• Store Data And Program In Memory.
• Data Processing.
• Send Output To Output Device.
• Control All Operations.

Program Execution

The program execution is the main function of the computer system. The computer system makes use of its hardware and software components to execute the program.

Various components such as memory ( RAM ) , CPU , input devices , output devices performs different functions together during the program execution.

Accept The Data From Input Devices

The computer system operates on the data as per the program instructions. The computer accepts the data through different types of input devices such as mouse , keyboard scanner and other input devices.

Store Data And Program In Memory

The computer stores the data and the program into its main memory RAM. The program is stored into the memory as set of instructions.

The CPU starts the program execution by fetching the data and instructions from the memory . The CPU sends the processed data back to the memory for the output devices.

Data Processing

The computers are extensively used for data processing jobs. The process converting the raw data into useful information is defined as data processing.

The data is processed as per the program instructions. For example , the monthly attendance data is converted into salary statements at the end of the month by using a payroll application software.

Send Output To Output Device

The output devices are used to send the result that can used by the user. The program output can either be sent to the monitor , printer , storage disks or any other output device.

Control All Operations

The computer system controls the operations of the software and hardware components. The control unit of the CPU ( central processing unit ) controls the operations of the entire computer system .

Types Of Computer Systems

Different types of computer systems are used for various applications in many fields. The system configuration can differ in terms of  processor architecture, number of processor, memory size, motherboard design and other factors.

• Desktop Computer.
• Palmtop Computer.
• Workstation Computer.
• Web Server Computer.
• Mini Computer.
• Mainframe Computer.
• Super Computer.
• Embedded Computer.

Computer System Architecture

What is computer system architecture .

In  computer engineering, the computer system  architecture is the conceptual design and fundamental operational structure of a computer system.

It is the technical drawings and functional description of all design components and  requirements . The system architecture defines the system performance parameters such as speed and interconnections .

The System architecture can also be defined as the science and art of selecting and interconnecting hardware components to create computer system that meet  functional , performance  and cost goals.

And therefore , better system architecture will produce a better design and system performance.

Computer Organization And Architecture ( COA )

The Computer system consist of four basic components Or Units . In terms of functionality , the computer system can be grouped in to four  basic units . 

• Input Unit ( Input Devices ).
• Central Processing Unit ( CPU ) .
• System Memory Unit .
• Output Unit ( Output Devices ) .

Computer Hardware

The  computer system  mainly  consist  of  hardware components  and  the  software components .   All  the  physical  components  inside  the computer cabinet  and  the  input  / output  gadgets  attached  to  the  computer  are  referred  as  hardware  components .

The hardware  components  inside the computer  cabinet  are referred  as  internal  components  such as  motherboard .The external  hardware components attached  to the computer  system  are also referred as peripheral  devices  such  as  keyboard , mouse , monitor  .

Computer Hardware Components

• Computer Cabinet ( Casing ).
• Power Supply Unit ( SMPS ).
• Motherboard .
• Connection Cables ( Buses ).
• Hard Disk ( Disk Memory ) .
• RAM Modules
• Sound Card.
• Microprocessor ( CPU ).
• CPU Heat Sink
• CPU Cooling Fan.
• CD ROM Drive.
• Graphics Card.
• Computer Monitor ( Display ).
• Keyboard And Mouse.

Computer System Motherboard

The motherboard is the main printed circuit board ( PCB ) that is mounted inside a computer cabinet. The motherboard  is a junction for connecting some important internal components .

The components that are directly placed on the motherboard include microprocessor ( CPU ) , main memory RAM , Graphic card , sound card , north bridge and south bridge.

Computer System Microprocessor

The central process ring unit ( CPU ) effectively functions as a brain of the computer system. The CPU performs arithmetic and logical operations and provides processing power of the computer system.

The CPU is mounted on the motherboard inside a processor socket which is a special slot  present on the motherboard. The processor chip is firmly mounted inside CPU socket  with help of liver locking mechanism.

A heat sink and a cooling miniature fan is placed on the top of the processor chip to protect the processor chip from excessive heat generated by the processor chip.

What Is Microprocessor ?

What is cpu , how cpu works , cpu functions.

The central processing unit ( CPU ) is also alternately referred to as microprocessor or processor .  The processor provides the processing power to the computer system .

The CPU performs number of vital functions . One of the the main function of the CPU is to execute the  computer program. 

The  control unit of the CPU is responsible to decode the machine instructions. The control unit decodes the program instructions as specified in the instruction format.

The CPU executes the computer program by repetitively performing a machine cycle which is a basic operation of the processor . The machine cycle consist of four steps . These machine cycle steps are : 

What Is Central Processing Unit ?

What is cpu machine cycle .

The operating system loads the program instructions and associated data into the main system memory RAM . The CPU fetches the data and program instructions ( machine instructions ) from the main memory RAM .

Main System Memory

Random Access Memory ( RAM )

The computer system makes use of different types of memories . These different types of memories are organized into the system in order to optimize the CPU performance.

The main system memory RAM ( Random Access Memory ) modules are mounted inside special RAM slots on the motherboard . Each motherboard has fixed number of RAM slots .

The maximum permissible RAM size ( 4 GB , 8GB , 16 GB ) supported by the system depends  upon the system configuration and the type operating system  ( 32 Bit OR 64 Bit OS ).

System - Power Supply Unit

The computer system has a centralized power supply unit that provides electrical power supply to various internal components .

The desktop computer system power system is referred as SMPS which stands for Switched Mode Power Supply . The SMPS provides different voltage of power supply to different components through set of electric wires.

Computer Software

The computer software is a  set program instructions designed to perform a specific tasks . A computer program is written  in  computer programming language such  as  C , C++ , Java   , python and so many other languages .

The  computer system makes use of two types of software .

• System Software .
• Application Software .

The System software is used by the system itself manage and control the system hardware components. The operating system communicates with the hardware components through system software . 

The System software includes Operating System ( OS ) ,device drivers and other system utility programs . The application software  are used by the computer user to perform various tasks on the system. The commonly used application software includes  MS Word , Excel .

System Software

What is system software .

In computer system architecture , the System Software  is a collection of programs designed to operate , control and extend  the processing capabilities  of  the computer system and the other hardware devices connected to the computer system.

The system  software  is also   designed and developed  by the computer manufacturer to  communicate  with  specific  hardware components connected  to  the  computer system.

For example when we connect a new device to the system , we need to first install the device driver to operate the device such as  camera , printer , scanner and other such devices .  

Both  application programs and the operating system needs a special software called device driver to  communicate and to drive the various hardware components connected to the computer system .

The device driver is a  system  software  which functions  as an interface between the computer  hardware  and  the operating system .

The  system software programs  are  generally  written  in  a low level programming  language   such  as assembly language . 

Application Software

The application software provides an interface to the computer user to perform a specific job on the computer system . For example , writing document , making presentation or managing accounts .

Application software are installed on the system to provide specific functionality to the system . The  Application software is  designed  and developed  to satisfy a specific  need  of the computer user  .

For  example MS Office , accounting  software ( Tally )  ,  engineering  drawing  software (  AutoCAD ) are some of commonly used application software.

Application  software  can  be  single  program application  or  a  group  of   programs  bundled together such  as  MS  Office . Each of these  program in a bundle has been  designed  to provide specific functionality  to the  user  .

Evolution Of Computers

The  Computers  are today integral part  of the human world  and human world today  critically depends  upon the  computing  power of  today’s modern computers . 

The applications of computers are indispensable part of every industry we can possibly think of .

The Computer Science and technology  has  also evolved  over period of last few decades both in the hardware technology and also in the software domain. 

However , The history of computer science began  , long before our today’s modern discipline of computer science.

In the past seventy years , the computers have evolved from room-size mega boxes to the desktops computers. And now, computers are  in  our pockets  with far  more computing power  and mobility.

But the modern computing-machine era began with Alan Turing’s conception of the Turing Machine, and the  invention of the transistor by three Bell Labs scientists.

The invention of transistor was a major breakthrough in the field of digital electronics . The transistor is tiny electronic component that used as a micro-switch in digital electronics .

The transistors soon replaced the bulky voles valves used in the second generation of computers. The transistors are fundamental building block of all modern processor chips . 

Turing Machine

The turing machine is an important mathematical computation model in the theory of computing . Although this model was first proposed and invented by Alan Turing in year 1936 .

The turing machine model is still considered to be a standard of computational model to verify a particular problem can be solved using a computer system .

Turing machine is still relevant despite the passage of time and the advancements in the various fields of computer science . Despite the simplicity of the model , the turing machine can simulate both simple and a very complex algorithm.

Computer Architecture

The CPU is the brain of the computer system which performs all the mathematical calculations and logical operations . The CPU consist of millions of tiny components called the transistor. 

The transistor functions as a micro switch that can be simulate the two binary states ( 0 and 1 ) .

The transistors are made-up of semiconductor material silicon. The transistor can easily functions as micro-switch to represent the two states ( ON – 1 And OFF – 0 ) in binary . The transistor  is a fundamental building block  for all digital electronic devices  including computers .

The  invention  of tiny electronic component transistor  was a major technological leap forward that has  made the modern-style computing possible today .

The invention of transistor was an important milestone in field of digital electronics   which rewarded  the three Bell lab scientists  with  the 1956 Nobel Prize in Physics . The Microprocessor consist of millions of these transistors.

Introduction To Computer FAQ

A computer is a digital electronic machine used to convert data into information. The computer will process the data as per the computer program instructions.

This is the most common application of the computer. A computer is also defined as programmable electronic machine used for data processing.

Computer Block Diagram

What Is Computer Software And Hardware ?

A computer system consists of software and hardware components. The software components are basically computer programs. Whereas, the hardware components are physical parts of the computer. Both hardware and software together forms a computer.

A computer is driven by a set of instructions which directs the computer to perform some specific tasks. This set of instructions is called a computer program.

A computer programs are written using a programming language. Different types of programming languages are used to write the program depending upon the application.

What Is Application Program ?

The application program is a type of computer program developed to allow the user to perform a specific task on the computer. For example, the user might need a calculator program to perform some calculations.

Similarly, the user use media player program to watch movies or to play some music on the computer. Microsoft word, PowerPoint, and excel are the most commonly used application program examples.  

A system software is a type of computer program internally used by the computer to manage the computer. The user generally interacts with the application programs.

Whereas, different types of system software are internally used by the computer to interact and communicate with various hardware components connected to the computer.

What is the main function of the computer ?

The main function of the computer is to execute the program. Computer is also said to be a dumb machine because it needs a program to execute the various user specified tasks.

What Is Operating System ?

An operating system is a type of system software and essential component of every computer system. The operating system provides an interface to the user to interact and perform various tasks on the computer.

The operating system is also responsible to manage some of the most important functions such system security, resource management, manage hardware components and user permissions.

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An introduction to computers and computer systems

Course description

Course content, course reviews.

This free course,  An introduction to computers and computer systems , challenges how we view computers through the examples of processors in kitchen scales and digital cameras, as well as examining the work of art that, at heart, is a computer. You will also explore how computers are connected together to achieve even more than when working alone.

Course learning outcomes

After studying this course, you should be able to:

• recognise the fundamental hardware components that make up a computer's hardware and the role of each of these components
• describe the difference between an operating system and an application program, and what each is used for in a computer
• understand something of the work involved in designing an application program
• appreciate some of the core networking technologies used to connect computers together
• reflect on some of the future directions for computers and computer systems.

First Published: 21/07/2021

Updated: 21/07/2021

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Computers and the Internet

Course: computers and the internet   >   unit 2, what are the parts of a computer.

• CPU, memory, input & output
• Input & output devices
• Central Processing Unit (CPU)
• Computer memory
• Secondary memory
• Computer components
• Exploring microcomputers

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revised: 01/18/99, 06/12/00, 01/09/02, 01/07/06, 07/31/06, 07/29/08, 06/17/10

CHAPTER 1 — Introduction to Computer Systems

A computer is a complex system consisting of both hardware and software components. This chapter discusses these components.

Chapter Topics:

• Hardware and Software
• Components of a Computer System
• World-Wide Web

QUESTION 1:

What do you think about the movie The Wizard of Oz ?

• Basics of Computers Tutorial
• Basics of Computers – Home
• Basics of Computers – Introduction
• Basics of Computers - Classifications
• Basics of Computers – S/W Concepts
• Basics of Computers – System S/W
• Functions of Operating System
• Types of Operating System
• Basics of Computers – Utility S/W
• Open Source Software
• Basics of Computers – Office Tools
• Domain Specific Tools
• Number System
• Number System Conversion
• Microprocessor Concepts
• Evolution of Microprocessor
• Primary Memory
• Secondary Memory
• Basics of Computers – I/O Ports
• Basics of Computers Resources
• Basics of Computers – Quick Guide
• Basics of Computers – Resources
• Basics of Computers – Discussion
• Selected Reading
• UPSC IAS Exams Notes
• Developer's Best Practices
• Questions and Answers
• Effective Resume Writing
• HR Interview Questions
• Computer Glossary

Basics of Computers - Introduction

Being a modern-day kid you must have used, seen, or read about computers. This is because they are an integral part of our everyday existence. Be it school, banks, shops, railway stations, hospital or your own home, computers are present everywhere, making our work easier and faster for us. As they are such integral parts of our lives, we must know what they are and how they function. Let us start with defining the term computer formally.

The literal meaning of computer is a device that can calculate. However, modern computers can do a lot more than calculate. Computer is an electronic device that receives input, stores or processes the input as per user instructions and provides output in desired format.

Input-Process-Output Model

Computer input is called data and the output obtained after processing it, based on user’s instructions is called information . Raw facts and figures which can be processed using arithmetic and logical operations to obtain information are called data .

The processes that can be applied to data are of two types −

Arithmetic operations − Examples include calculations like addition, subtraction, differentials, square root, etc.

• Logical operations − Examples include comparison operations like greater than, less than, equal to, opposite, etc.

The corresponding figure for an actual computer looks something like this −

The basic parts of a computer are as follows −

Input Unit − Devices like keyboard and mouse that are used to input data and instructions to the computer are called input unit.

Output Unit − Devices like printer and visual display unit that are used to provide information to the user in desired format are called output unit.

Control Unit − As the name suggests, this unit controls all the functions of the computer. All devices or parts of computer interact through the control unit.

Arithmetic Logic Unit − This is the brain of the computer where all arithmetic operations and logical operations take place.

Memory − All input data, instructions and data interim to the processes are stored in the memory. Memory is of two types – primary memory and secondary memory . Primary memory resides within the CPU whereas secondary memory is external to it.

Control unit, arithmetic logic unit and memory are together called the central processing unit or CPU . Computer devices like keyboard, mouse, printer, etc. that we can see and touch are the hardware components of a computer. The set of instructions or programs that make the computer function using these hardware parts are called software . We cannot see or touch software. Both hardware and software are necessary for working of a computer.

Characteristics of Computer

To understand why computers are such an important part of our lives, let us look at some of its characteristics −

Speed − Typically, a computer can carry out 3-4 million instructions per second.

Accuracy − Computers exhibit a very high degree of accuracy. Errors that may occur are usually due to inaccurate data, wrong instructions or bug in chips – all human errors.

Reliability − Computers can carry out same type of work repeatedly without throwing up errors due to tiredness or boredom, which are very common among humans.

Versatility − Computers can carry out a wide range of work from data entry and ticket booking to complex mathematical calculations and continuous astronomical observations. If you can input the necessary data with correct instructions, computer will do the processing.

Storage Capacity − Computers can store a very large amount of data at a fraction of cost of traditional storage of files. Also, data is safe from normal wear and tear associated with paper.

Advantages of Using Computer

Now that we know the characteristics of computers, we can see the advantages that computers offer−

Computers can do the same task repetitively with same accuracy.

Computers do not get tired or bored.

Computers can take up routine tasks while releasing human resource for more intelligent functions.

Disadvantages of Using Computer

Despite so many advantages, computers have some disadvantages of their own −

Computers have no intelligence; they follow the instructions blindly without considering the outcome.

Regular electric supply is necessary to make computers work, which could prove difficult everywhere especially in developing nations.

Starting a computer or a computer-embedded device is called booting . Booting takes place in two steps −

• Switching on power supply
• Loading operating system into computer’s main memory
• Keeping all applications in a state of readiness in case needed by the user

The first program or set of instructions that run when the computer is switched on is called BIOS or Basic Input Output System . BIOS is a firmware , i.e. a piece of software permanently programmed into the hardware.

If a system is already running but needs to be restarted, it is called rebooting . Rebooting may be required if a software or hardware has been installed or system is unusually slow.

There are two types of booting −

Cold Booting − When the system is started by switching on the power supply it is called cold booting. The next step in cold booting is loading of BIOS.

Warm Booting − When the system is already running and needs to be restarted or rebooted, it is called warm booting. Warm booting is faster than cold booting because BIOS is not reloaded.

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Computer || Introduction, Definition, Parts & Types

Introduction of Computer A computer is a fast and accurate electronic machine that is designed to accept and store input…

Table of Contents

Introduction of Computer

• A computer is a fast and accurate electronic machine that is designed to accept and store input data, process them and produce output results, using the instructions of a stored program or data.
• A computer has some wonderful features that make it different from a human.
• It has become a critical piece of our lives.
• The word computer brings from the word ‘ compute ‘, that means to ‘ calculate .’
• The function performed by a PC is execution of program.
• A computer understand ‘ Binary ‘ language only.
• It produces 100 percent accurate results.
• Charles Babbage is considered as the dad of computer.
• He was an English mathematician and inventor.

Definition of Computer

• A computer is a fast data processing electronic machine in which a program is set of instruction or commands.
• It performs the arithmetical and logical operations on the input data and gives the desired output.

Working of Computer

• A computer works on the three basic steps:-
• This whole process is term as input- process- output cycle or I- P- O cycle.

Working of I- P- O cycle

• Let us learn with an example how I- P- O cycle works in a computer.
• Shilpa wants to add 18 and 17. So, she open the calculator on her computer and click on the buttons 18+ 17 =
• Input: The data and instructions that we enter into the computer are called as input. We input data using a keyboard and mouse.
• Here, data ( 18, 17 ) and instruction ( +, = ) acts as input.
• Process: Working on data is called as processing. The CPU works on data and does all the thinking and calculation.
• The computer finally gives the sum as 35.
• Output: The finally information we get is the output.
• The monitor shows the output.

Input:- 18, 17, +, =

Process:- 18 + 17 =

Output:- 35

Generations of Computer

• The term ” generation ” is generally used to characterise the major developments in the field of computer industry.
• There is no clear- cut separating line between the generations.
• Basically, the term generation is used to distinguish between different hardware technologies developed.
• Generations of a computers are divided into five categories. They are named as:-

1. First Generation of computer

2. Second Generation of computer

3. Third Generation of computer

4. Fourth Generation of computer

5. Future Generation of computer

• The 1st generation of computer is developed by Eckert and Mauchly in 1946 in the USA .
• They are named as Electronic Numerical Integrator and Calculator.
• In short ENIAC.
• It used high speed vacuum tubes as switching devices and had a tiny memory.
• The ENICA took about 200 microseconds to add two digits and about 2400 microseconds to multiple.
• In 1946 , Professor John V Neumann proposed the concept of stored programming that is the storage of machine instructions in the memory of the computer in 1949 known as EDSAC .
• EDSAC is represents Electronic Delay Storage Automatic Calculator.
• It used mercury delay lines for storage.
• The 1st commercial production of stored electronic computers was UNIVAC .
• UNIVAC is stand for Universal Automatic Computer.
• During this period, PC writing computer programs was predominantly done in the machine language.
• Assembly language was presented during the early fifties.

Characteristics of 1st Generation of Computers

• It has a vacuum tube circuit.
• Continuous maintenance required.
• Punched card and paper tape utilized as secondary storage.
• Dump primary storage.
• Machine and symbolic language programming.
• Generated considerable heat.
• Poor reliability.
• Limited internal storage capacity.
• First commercial computer to be used.
• Slow input/output operations.
• Computer programmed with machine language.
• The 2nd generation of computers stared around 1956 .
• In this age, the computers used transistors instead of vacuum tubes.
• Transistors were made of germanium semi- conductor material.
• They were exceptionally solid when contrasted with tubes.
• Another major breakthrough during this period was the invention of magnetic core for storage.
• Developments of assembly language, assembler and procedural high- level language like Fortran, Cobol, Algol, Snobol, etc. were developed.
• Also, commercial applications like Payroll, Inventory Control and Production Planning and General Ledger System were developed.

Characteristics of 2nd Generation of Computers

• In a core element transistor circuit was used.
• Magnetic core primary storage.
• Secondary storage on tapes.
• Greater reliability and speed.
• Reduced generated heat.
• Smaller and more reliable.
• Faster than 1st generation computers.
• Required less power to operate.
• High level procedural languages Fortran and Cobol were utilized.
• Computers programmed in high level languages.
• The 3rd generation started in the year 1965 .
• In this generation, Germanium transistors were the core element replaced by silicon transistors.
• Here, the transistors were comprised of small scale integrated circuits, consisting of transistors, resistors, and capacitors, grown on a single chip of silicon.
• Hundred or even thousands of transistors could be manufactured on a single wafer of silicon.
• The size of main memory reached about 100 megabytes.
• FORTRANIV, COBOL- 68, PL/1 , etc. were other high level languages developed during this period.
• Additionally, the developments and usage of compiler and interpreter were used in programming languages.
• There are many important on line systems like airline reservation, dynamic production control, interactive query and integrated database management systems emerged on the global software scenario.

Characteristics of 3rd Generation of Computers

• Transistors were replaced by integrated circuits.
• Increased speed and reliability.
• Development of minicomputers.
• On line, real time processing.
• Multiprogramming operating system was introduced.
• It was faster than the previous generation.
• To improved input and output devices.
• The 4th generation was stared in the years 1976 – 1985 .
• This generation emerged with the large scale integrated circuits ( LSIC ) and very large integrated circuits ( VLSIC ) .
• There were packed about 50,000 transistors in a single chip.
• Personal computers were manufactured rapidly.
• Floppy disks served as low cost, high limit reinforcement peripherals.
• A significant development in software was the improvement of the most ambitious language ADA.
• And another development was in the field of interactive graphics.

Characteristics of 4th Generation of Computers

• The 4th generation computer used LSI and VLSI technology.
• Dramatic rise in hardware costs.
• Semi- conductor primary storage was used.
• Development of microcomputer or personal computer.
• Increased costs of software.
• Advancement of electronic spreadsheets and database management systems.
• Compact in size but faster speeds of processing.
• Microprocessor was used.
• An effective 5th generation computer would be highly complex and intelligent electronic device conceived with an idea of intelligence without going through the various stages of technical development.
• This idea of intelligence is called artificial intelligence or AI .
• The emphasis is now shifting developing reliable, faster, and smaller but dump machines to more intelligent machines.

Parts of Computer

• A computer is made up of different parts which are named as:-

1. The motherboard

2. The Central Processing Unit

3. A Graphics Processing Unit

4. A Random Access Memory

5. External Hard Drive

6. An Optical Drive

7. Solid State Drive

8. USB Flash Drive

9. Hard Disk Drive

10. A Card Reader

11. A Monitor

12. A keyboard

13. A mouse

14. Printer

15. Projector

16. Joystick

• The motherboard is the primary component of a PC.
• It is a board with integrated circuitry that interfaces different pieces of the PC including the CPU, RAM , disk drives just as any peripherals associated by means of the ports or the extension openings.
• It contains ports to interface every one of the inner parts.
• It carries a special port designed for power supply or fans.

• The central processing unit is written in short form as CPU.
• The CPU is called as the brain of the computer.
• This is where PC does all its processing work.
• It also controls all input, output and other devices.
• Inside CPU there is a box known as the CPU box.
• It is taken program guidelines from RAM , interprets and processes them and then sends back results so that the relevant components can easily carry out the instructions.
• They are usually cooled by a heat sink and fan, or water-cooling system.
• Most fresher CPU incorporates an on-die graphics preparing unit  (GPU).
• The clock speed of CPU governs how quick it executes guidelines and is measured in GHz ; normal qualities lie between in the range of 1 GHz and 5 GHz.
• A Graphics Processing Unit is written in short form as GPU.
• A GPU is a chip or electronic circuit fit for rendering graphics for show on an electronic gadget which was acquainted with the more extensive market in year 1999 .
• It is best known for its use in providing the smooth graphics that consumers expect in modern games and videos.
• It comprise of polygonal directions that are changed over designs in recordings and games into bitmaps—a cycle called “ delivering “.
• And after that converted into signals that are shown on a screen.
• This transformation requires GPU to have a lot of processing power, which also makes GPUs valuable in machine learning, artificial knowledge, and different tasks that require a large number of complex and sophisticated computations.

• A random access memory is written in short form as RAM.
• A RAM is a form of PC memory that can be read and changed in any order, regularly used to store working information and machine code.
• A RAM permits data items to be read or written in practically a similar amount of time independent of the actual area of data inside the memory.
• It stands out from other direct-access information storage media where the time needed to read and write data items varies significantly depending on their actual locations on the recording medium, because of mechanical limitations for example as media rotation speeds and arm movement.
• An external hard drive is a gadget that you plug into a PC port.
• An external hard drive gives you more extra space to keep your information.
• At the point when you store information on an outside hard drive, you can possibly get to it when the hard drive is connected to your PC .
• We can use an outer hard drive to store documents that you don’t get to every now and again for example, Old photographs or recordings, records and chronicled information, finished activities/portfolios and so on.
• An optical drive refers to a PC system that permits users to utilize DVDs, CDs and Blu-ray optical drives.
• The drive contains a couple of focal points that project electromagnetic waves that are liable for perusing and composing data on optical plates.
• An optical drives are fundamental pieces of hardware gadgets like VCD players, CD players, Blu-ray players, DVD players, and certain computer games control center like Microsoft Xbox one, Sony PlayStation 2, 3&4 and Nintendo Wii U .
• A solid-state drive is written in short form as SSD.
• A SSD is a solid-state storage device that uses integrated circuit congregations to store information constantly, typically utilizing streak memory, and filling in as optional stockpiling in the order of PC amassing.
• It is likewise now and again called a solid-state device or a solid-state disk, even however SSDs do not have the physical spinning disks and movable read–compose heads used in hard plate drives  (HDDs) and floppy circles.
• A USB flash drive is a data limit device that includes flash memory with an integrated USB interface.
• It is typically removable, rewritable and a lot more smaller than an optical disc.
• It is often used for storage, data back-up and transferring of PC files.
• A hard disk drive is written in short form as HDD.
• A PC HDD is a non-shaky memory equipment gadget that controls the arranging, perusing and composing of the hard plate, which outfits information stockpiling.
• It is commonly used as the main storage device in a PC.
• In a PC, HDD is generally found in the drive bay and is related with the motherboard through an ATA, SATA or SCSI connect.
• The HDD is likewise related to a power supply unit and can keep stored information while powered down.
• A  card reader is a data input device that peruses data from a card-shaped storage medium.
• The first were punched card readers, which read the paper or cardboard punched cards that were utilized during the initial quite a few years of the PC business to store data and projects for PC frameworks.

• A monitor is an output device that shows data in pictorial construction.
• A monitor usually includes the visual display, circuitry, packaging, and power supply.
• It looks like a TV screen.
• Whatever we type with the help of  keyboard can be seen on the monitor.
• It is also called as VDU.
• VDU stands for Visual Display Unit.
• The output we get on the monitor is called a soft copy .
• There are two types of monitor.
• LCD and CRT monitor.
• LCD is stand for Liquid Crystal Display and CTR is stand for Cathode Ray Tube.
• A keyboard is the most common input device used to enter data and instructions into the PC.
• A keyboard has many keys on it.
• There are various types of keyboard layouts manufactured based on the region and language utilized.

• A mouse is a hand held pointing device with two or three buttons on its top.
• It is used to select and point things on the monitor.
• It can also be used to draw pictures.
• A printer prints the output which we see on the PC screen on paper.
• The printer copy is called the hard copy.
• There are three main types of printer.

A. Dot matrix printer

B. Inkjet printer

C. Laser printer

• A  dot matrix printer is an impact printer that prints utilizing a fixed number of pins or wires.
• In a dot matrix printer the pins or wires are organized in one or a few vertical segments.
• The pins strike an ink-covered lace and power contact between the lace and the paper, so that each pin makes a little dab on the paper.
• Thus mix of these specks shapes a spot lattice picture.
• They were also called as serial dot matrix printers .
• A Inkjet printing  is a type of PC printing that reproduces a digital picture by impelling beads of ink onto paper and plastic substrates.
• These are the most commonly used type of printer, and reach from little reasonable customer models to costly expert machines.
• There are 2 main technologies which are in use in contemporary inkjet printers: continuous (CIJ) and drop-on-demand (DOD).
• A continuous inkjet means the flow is compressed and in a relentless stream.
• A drop-on-demand means the fluid is expelled from jet nozzle one drop at a time.
• This should be possible with a mechanical method with a push or some electrical technique.
• A Laser printing is an electrostatic computerized printing measure.
• It creates high-quality text and graphics by more than once passing a laser beam back and forth over a negatively charged cylinder called a “drum” to characterize a differentially charged image.
• The drum then, at that point specifically gathers electrically charged powdered ink, and moves the picture to paper, which is then heated in order to permanently fuse the text, imagery, or both, to the paper.
• Similarly as with digital photocopiers, laser printers employ a xerographic printing measure.
• A Laser printing differs from conventional xerography as carried out in simple scanners in that in the last mentioned, the image is formed by reflecting light off an existing document onto the uncovered drum.
• A projector is an optical device that takes pictures produced by a PC or Blu-beam player and reproduce them by projection onto a screen, wall, or another surface.
• The images may be movable or either slides.
• It is often about the size of a toaster and weighs only a few pounds.
• Real-time, Still images, Moving images are three categories of a projectors that are based on the type of their input. 

• We use a joystick to play games on the PC.
• It helps us to control the movement of the pointer on the screen.
• It is stands for Uninterrupted Power Supply.
• It keeps the PC ON for some time even after the electricity goes OFF .
• It also saves the PC in case of high voltage or power problem.

Types of Computers

• On the basis of their performance and capacity computers are classified into 4 types. They are named as:-

1. Super computers

2. Mainframe computers

3. Mini computers

4. Microcomputers

• Super computers are the most powerful computers.
• They are also the most expensive PC.
• They are used for complex operations like astronomy, automobile designing, aircraft designing, space explorations, weather forecasting, etc.
• The performance of a supercomputer is commonly measured in floating-point operations per second rather than million instructions per second.
• Mainframe computers have a huge storage capacity.
• They can process data at a very high speed and they are also quite expensive.
• These PCs are generally used in large industries, banks and in scientific research centres.
• IBM-570 is a popular series of mainframe computers.
• Mini computers are less advanced as compared to mainframe computers in terms of speed and storage capacity.
• They are likewise more affordable than centralized server PCs.
• These PCs are mostly used as network servers and internet servers.
• PDP-8 and VAX PCs are examples of mini computers.
• Personal PCs, commonly used in schools, homes, offices, banks, etc. are known as microcomputers.
• These PCs are small with compact technology.
• The microcomputers were 1st developed by IBM corporation in 1981.
• Some other manufacturers are Dell, Apple, and HP .
• Desktop computers, laptops and palmtops are different types of microcomputers.
• Desktop PC are big in size and can be kept on a desk.
• Laptops as the name clearly indicates, are small enough to be carried easily while travelling.
• We can keep them on your lap and conveniently use them.
• These PC can be work with the help of batteries for a very long time.
• Tablets and palmtops are smaller than laptops and can be carried along easily.

Characteristics of a Computer

• There are 5th important characteristics of a computer which makes it a very special machine. They are as follows:-

2. Accuracy

3. Diligence

4. Versatility

5. Storage capacity

• A PC can perform operations at a very fast speed.
• It can perform thousands of mathematical operations in just a few seconds.
• The time it takes to perform these calculations is measured in the terms of nanoseconds or picoseconds.

1 second = 10 9  nanoseconds 

1 seconds = 10 12   picoseconds

• A PC is considered to be 100% accurate, provided the data and instructions given to it by the user are up to the mark.
• A PC can work continuously for hours without getting tired.
• The speed and  accuracy level also remains the same, even after it works for many hours.
• The same PC machine can be used for performing various jobs.
• It suits the needs of different kinds of people involved in different professions.
• A PC can store huge amount of data and information in its storage, called memory.
• This stored information can be kept and used for a long time.

Advantages of Using a Computer

• To increase our productivity.
• To connects us to the internet.
• It reduce waste and can store vast amount of data.
• To improves our employment options.
• To save the time.
• To assist the physical challenged.
• Also find your love in your life.
• To keep us entertained.
• To help us automate and monitor.
• To gave you a better understanding of data.
• They help us organize, sort and search through information .

Limitations of a Computer

• There are no decision making ability.
• It has no intelligence.
• They don’t have emotions and feelings.

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CS101: Introduction to Computer Science I (2019.A.01)

Introduction to Computer Systems

Review these notes. For maximum benefit, go through these notes interactively, thinking about and answering the questions at the bottom of each page. These notes are an experiment in applying the "programmed learning" method to web-based computer aided instruction. The subject is Java Programming for beginning programmers. The content is intended to start beginning programmers out on the track to professional-level programming and reinforce learning by providing abundant feedback. Java is a programming language that is used often in professional practice.

Components of a Computer System

chap01-03.mp3

No. You have destroyed a particular physical book, but not the information that is the novel  Tom Sawyer . (You will still have to write that book report.)

Information is funny stuff. The information for the web page you are looking at is recorded on a hard disk inside a computer located in New Britain, Connecticut. The information was copied from that physical device to other physical devices perhaps hundreds of times before it got to your computer where your web browser is using it to display these words on your monitor. Clearly information is something different from the devices used to store and transmit it.

A computer system consists of both hardware and information stored on hardware. Information stored on computer hardware is often called  software .

The  hardware  components of a computer system are the electronic and mechanical parts.

The  software  components of a computer system are the data and the computer programs.

The major hardware components of a computer system are:

• Main memory
• Secondary memory
• Input devices
• Output devices

For typical desktop computers, the processor, main memory, secondary memory, power supply, and supporting hardware are housed in a metal case. Many of the components are connected to the main circuit board of the computer, called the  motherboard . The  power supply  supplies power for most of the components. Various input devices (such as the keyboard) and output devices (such as the monitor) are attached through connectors at the rear of the case.

Question 3:

Is a  mouse  an input device or an output device?

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The ICS course provides a programmer's view of how computer systems execute programs, store information, and communicate. It enables students to become more effective programmers, especially in dealing with issues of performance, portability and robustness. It also serves as a foundation for courses on compilers, networks, operating systems, and computer architecture, where a deeper understanding of systems-level issues is required. Topics covered include: machine-level code and its generation by optimizing compilers, performance evaluation and optimization, computer arithmetic, memory organization and management, networking technology and protocols, and supporting concurrent computation.

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An Introduction to Operating System

An Operating system forms the core of any computer device. The functioning and processing of a computer system can come to hold without an operating system.

In this article, we shall discuss in detail the Operating System, along with its various types and functions. The different features and history of the development of OS have also been discussed. For the reference of competitive exam aspirants, some sample questions have also been given further below in this article. 

To comprehend Computer Knowledge and its key features, understanding this concept becomes a key factor. Thus, one must carefully go through the various aspects related to this topic to understand it well.

Before moving forward, let us first know What is an Operating System?

An Operating System is the interface between the computer hardware and the end-user. Processing of data, running applications, file management and handling the memory is all managed by the computer OS. Windows, Mac, Android etc. Are examples of Operating systems which are generally used nowadays.

All modern computing devices including Laptops, Tablet, mobile phones, etc. comprise an Operating System which helps in the smooth working of the device.

History of the Operating System

It took years to evolve the Operating Systems and make them as modernised and advanced as they are today. Given below are the details about the evolution and history of Operating systems.

• Initially, the computers made did not have an Operating system and to run each program a different code was used. This had made the processing of data more complex and time taking
• In 1956, the first operating systems were developed by General Motors to run a single IBM computer
• It was in the 1960s that IBM had started installing OS in the devices they launched
• The first version of the UNIX operating system was launched in the 1960s and was written in the programming language C
• Later on, Microsoft came up with their OS on the request of IBM
• Today, all major computer devices have an operating system, each performing the same functions but with slightly different features

To read more about MS Windows , the Operating system released by Microsoft, visit the linked article. 

Types of Operating System

Given below are the different types of Operating System along with  brief information about each of them:

1. Batch Operating System

• There is no direct communication between the computer and the OS
• There is an intermediate, the Operator, which needs to distribute the work into batches and sort similar jobs
• Multiple users can use it
• Can easily manager a large amount of work

2. Real-Time Operating System

• It has a data processing system
• The processing time is very small between the user’s command and the output
• Used in fields where the response needs to be quick and rapid

3. Time-Sharing Operating System

• Multiple people at various terminals can use a program at the same time 
• The main motive is to minimize the response time

4. Distributed Operating System

• When two or more systems are connected to each other and one can open files which are not present in their system but in other devices connected in the network
• Its usage has now increased over the years
• They use multiple central processors to serve real-time applications
• Failure of one system does not affect the other systems connected in the network

5. Embedded Operating System

• These special Operating systems are built into larger systems
• They generally are limited to single specific functions like an ATM

6. Network Operating System

• They have one main server which is connected to other client servers
• All the management of files, processing of data, access to sharing files, etc. are performed over this small network
• It is also a secure operating system for working with multiple users

7. Mobile Operating System

• With the advancement in the field of technology, smartphones now are released with an Operating system. 
• They are designed in a manner that they can help a small device work efficiently

To read in detail about the Fundamentals of Computer , visit the linked article.

Functions of Operating System

Given below are the various functions of an Operating System:

• It helps with memory management. It keeps a track of the files being saved in the Main memory and the primary memory of the computer device
• Whenever a computer is turned on, the Operating system automatically starts to work. Thus, the booting and rebooting process of a computer device is also an important function of the OS
• It provides a user interface
• Managing of basic peripheral devices is done by the operating system
• Using the password protection option of an operating system, the data in the device can be kept secure
• It coordinates with the software and the user
• Easy navigation and organisation of files and programs are managed by the OS
• Any kind of program which needs to be run through the system is done by the operating system
• If any kind of error or bug is found during the program is detected using the operating system

List of Common Operating Systems

Given below is a list of commonly used Operating systems along with their year of release. 

To know more about Microsoft Windows and its features, candidates can visit the linked article.

Sample Questions on Operating System

Computer Awareness is an important part of the syllabus for major Government and competitive exams conducted in the country. Questions in the form of MCQ are generally asked in these examinations and candidates must prepare themselves well enough to score more.

Given below are a few sample questions on the topic of Operating System and aspirants can refer to these to apprehend the type of questions and the pattern in which they may be asked.

To get the best Preparation Strategy for Competitive Exams , candidates can visit the linked article.  

Q 1. The __________ connects applications to the actual processing of data and manages all communications between software and hardware components. It is the core of any OS.

• Central Processing Unit
• Main Memory
• Systematic Multi-Processing
• Cluster Unit

Answer: (3) Kernel

Q 2. Which of the following options is not an Operating System?

• Blackberry OS

Answer: (4) Oracle

Q 3. Which of these is not a type of Operating System?

• Network Operating System
• Distributed Operating System
• Embedded Operating System
• Batch Operating System
• All are a type of Operating System

Answer: (5) All are a type of Operating System

Q 4. The first Operating System was developed by _____

• General Motors

Answer: (5) General Motors

Q 5. A program that automates the translation of assembly language into machine language is called _________

• Interpreter
• None of the above

Answer: (1) Assembler

The information given in this article will help aspirants comprehend the Operating System and its users in a much easier and understandable manner. 

Furthermore, to get the latest exam information and the best study material for competitive exams, visit BYJU’S.

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• CBSE Class 12 Accountancy Notes

Chapter 1: Accounting for Non-for-Profit Organization

• Not for Profit Organisations- Features and Financial Statements
• Difference Between Not for Profit Organisation and Profit Earning Organisation
• Income and Expenditure Account of a Not for Profit Organisation
• Difference between Receipt and Payment Account And Income and Expenditure Account
• Accounting Treatment for Subscriptions and Expenses
• Accounting Treatment of Consumable Items: Stationery and Sports Material
• Accounting Treatment: Admission or Entrance Fees, Donation and Legacies, Grants from Government, Sale of Fixed Assets, Life Membership Fees
• Fund based Accounting
• Receipt and Payment Account for Not for Profit Organisation
• Income & Expenditure Account: Accounting Treatment
• Balance Sheet for Not for Profit Organisation
• Practical Questions on Balance sheet for Not for Profit Organisation
• Practical Questions on Receipt & Payment Account

Chapter 2: Accounting for Partnership: Basic Concepts

• Introduction to Accounting for Partnership
• Partnership Deed and Provisions of the Indian Partnership Act 1932
• Difference between Limited Liability Partnership and Partnership Firm
• Accounting Treatment for Interest on Partner's Capital
• Interest on Drawing in case of Partnership
• Accounting Treatment of Partner's Loan, Rent Paid to a Partner, Commission Payable to a Partner, Manager's Commission on Net Profit
• Introduction to Profit and Loss Appropriation Account
• Difference between Profit and Loss Account And Profit and Loss Appropriation Account
• Capital Accounts of the Partner: Fixed Capital Method
• Capital Accounts of the Partner: Fluctuating Capital Method
• Difference between Fixed Capital Account and Fluctuating Capital Account
• Past Adjustments in Partnership
• Guarantee of Minimum Profit to a Partner

Chapter 3: Reconstitution of a Partnership Firm: Change in Profit Sharing Ratio

• Reconstitution of a Partnership Firm : Reasons and Change in Profit Sharing Ratio
• Goodwill: Meaning, Factors Affecting Goodwill and Need for Valuation
• Methods of Valuation of Goodwill
• Average Profit Method of calculating Goodwill
• Super Profit Method of Calculating Goodwill
• Capitalisation Method of Calculating Goodwill
• Accounting Treatment of Accumulated Profits and Reserves: Change in Profit Sharing Ratio
• Accounting Treatment of Workmen Compensation Reserve: Change in Profit Sharing Ratio
• Change in Profit Sharing Ratio: Accounting Treatment of Investment Fluctuation Fund
• Accounting Treatment of Revaluation of Assets and Liabilities: Change in Profit Sharing Ratio
• Accounting Treatment of Partner's Capital Account in case of change in Profit Sharing Ratio (Fixed Capital)
• Accounting Treatment of Partner's Capital Account in case of change in Profit Sharing Ratio (Fluctuating Capital)
• Adjustment in Existing Partner's Capital Account in case of Change in Profit Sharing Ratio

Chapter 4: Reconstitution of a Partnership Firm: Admission of a Partner

• Computation of New Profit Sharing Ratio: Admission of a Partner
• Computation of Sacrificing Ratio in case of Admission of a Partner
• Accounting Treatment of Goodwill in case of Admission of a Partner
• Hidden Goodwill: Admission of a Partner
• Accounting Treatment of Revaluation of Assets and Liabilities in case of Admission of a Partner
• Accounting Treatment of Accumulated Profits and Reserves in case of Admission of a Partner
• Accounting Treatment of Workmen Compensation Reserve: Admission of a Partner
• Accounting Treatment of Investment Fluctuation Fund in case of Admission of a Partner
• Accounting Treatment of Partner's Capital Account: Admission of a Partner (Fixed Capital)
• Accounting Treatment of Partner's Capital Account: Admission of a Partner (Fluctuating Capital)
• Preparation of Revaluation Account, Capital Account and Balance Sheet
• Adjustment of Partner's Capital Account: Admission of a Partner

Chapter 5: Reconstitution of a Partnership Firm: Retirement or Death of a Partner

• Retirement of a Partner in case of Reconstitution of a Partnership Firm
• Computation of New Profit Sharing Ratio: Retirement of a Partner
• Calculation of Gaining Ratio: Retirement of a Partner
• Difference between Sacrificing Ratio and Gaining Ratio
• Accounting Treatment of Goodwill in case of Retirement of a Partner
• Hidden Goodwill in case of Retirement of a Partner
• Accounting Treatment of Revaluation of Assets and Liabilities in case of Retirement of a Partner
• Accounting Treatment of Accumulated Profits and Reserves in case of Retirement of a Partner
• Accounting Treatment of Workmen Compensation Reserve in case of Retirement of a Partner
• Accounting Treatment of Investment Fluctuation Fund in case of Retirement of a Partner
• Accounting Treatment of Partner's Capital Account in case of Retirement of a Partner (Fixed Capital)
• Accounting Treatment of Partner's Capital Account in case of Retirement of a Partner (Fluctuating Capital)
• Settlement of Amount due to a Retiring Partner when Full Amount is Paid
• Settlement of Amount due to a Retiring Partner: Amount Paid in Instalment
• Settlement of Amount due to a Retiring Partner: Transferred to Loan Account
• Adjustment of Capital Account in case of Retirement of a Partner
• Reconstitution of a Partnership Firm in case of Death of a Partner
• Calculation of Share of Profit up to the Date of Death of a Partner
• Adjustment of Interest on Deceased Partner's Capital, Deceased Partner's Share in Goodwill and Accumulated Profits and Reserves
• Accounting Treatment of Revaluation of Assets and Liabilities in case of Death of a Partner
• Accounting Treatment of Accumulated Profits and Reserves in case of Death of a Partner
• Accounting Treatment of Workmen Compensation Reserve in case of Death of a Partner
• Accounting Treatment of Investment Fluctuation Fund in case of Death of a Partner
• Accounting Treatment of Partner's Capital Account in case of Death of a Partner (Fixed Capital)
• Accounting Treatment of Partner's Capital Account in case of Death of a Partner (Fluctuating Capital)
• Accounting Treatment of Amount Due to Deceased Partner
• Accounting Treatment of Joint Life Policy in case of Death of a Partner
• Accounting Treatment of Individual Life Policy in case of Death of a Partner

Chapter 6: Dissolution of Partnership Firm

• Dissolution of a Partnership Firm: Meaning, Modes of Dissolution, Modes of Settlement of accounts (Section 48)
• Difference between Dissolution of Firm and Dissolution of Partnership
• Difference between Firm's Debt and Private Debt
• Difference between Realisation account and Revaluation account
• Accounting treatment of Accumulated Profits, Reserves, and Losses in case of Dissolution of Firm
• Dissolution of Firm: Partner's Capital Account
• Dissolution of Partnership Firm: Meaning and Example
• Accounting Treatment of Goodwill in case of Dissolution of Firm
• Accounting Treatment of Joint Life Policy in case of Dissolution of a Firm
• Accounting Treatment of Contingent Assets and Contingent Liabilities in case of Dissolution of a firm

Chapter 7: Accounting for Share Capital

• Company and its Types
• Difference between Public Company and Private Company
• Types of Shares
• Difference between Preference Shares and Equity Shares
• Share Capital: Meaning, Kinds, and Presentation of Share Capital in Company's Balance Sheet
• Difference between Capital Reserve and Reserve Capital
• Accounting for Share Capital: Issues of Shares for Cash
• Issue of Shares At Par: Accounting Entries
• Issue of Shares at Premium: Accounting Entries
• Issue of Share for Consideration other than Cash: Accounting for Share Capital
• Issue of Shares: Accounting Entries on Full Subscription with Share Application
• Calls in Arrear: Accounting Entries on Issue of Shares
• Calls in Advance: Accounting Entries on Issue of Shares
• Oversubscription of Shares: Accounting Treatment
• Oversubscription of Shares: Pro-rata Allotment
• Oversubscription of Shares: Pro-rata Allotment with Calls in Arrear
• Forfeiture of Shares : Accounting Entries on Issue of Shares
• Accounting Entries on Re-issue of Forfeited Shares
• Disclosure of Share Capital in the Balance Sheet: Accounting Entries on Issue of Shares

Chapter 8: Issue and Redemption of Debentures

• Issue of Debentures: Meaning, Characteristics, Purpose of Issuing Debentures and Example
• Types of Debentures
• Difference between Shares and Debentures
• Issue of Debentures: Accounting Treatment of Issue of Debenture and Presentation of debentures in balance sheet (with format)
• Issue of Debenture at Par and Premium
• Issue of Debentures for Consideration other than Cash
• Issue of Debenture as Collateral Security
• Interest on Debentures
• Redemption of Debentures
• Redemption of Debentures: Meaning, Sources and Rules regarding Redemption
• Redemption of Debentures in case of Lump-Sum
• Redemption of Debentures in case of Installment
• Redemption of Debentures in case of Purchase of Own Debentures
• Redemption of Debentures: Conversion into Shares or New Debentures

Part-B Chapter 1: Financial Statements of a Company

• Financial Statements | Meaning, Objectives, Types and Format
• Objectives and Characteristics of Financial Statements
• Financial Statement of a Company: Balance Sheet
• Profit and Loss Account - Meaning, Format and General Instructions

Chapter 2: Analysis of Financial Statements

• Financial Analysis: Need, Types, and Limitations
• Financial Analysis: Uses, Importance, Limitations
• Comparative Statement: Meaning, Importance and Techniques of Presenting Financial Statements
• Comparative Balance Sheet: Objectives, Advantages and Format of Comparative Balance Sheet
• Comparative Income Statement: Objectives, Advantages and Preparation and Format of Comparative Income Statement
• Common Size Income Statement: Objectives, Preparation, Format of Common Size Statement
• Common Size Balance Sheet: Meaning, Objectives and Format of Common Size Balance Sheet

Chapter 3: Accounting Ratios

• Ratio Analysis- Importance, Advantages and Limitations
• Liquidity Ratio: Meaning, Types, Formula and Illustrations
• Current Ratio: Meaning, Significance and Examples
• Liquid/Quick Ratio: Meaning, Formula, Significance and Examples
• Solvency Ratio: Meaning, Formula, and Significance
• Debt-Equity Ratio: Meaning, Formula, Significance and Examples
• Total Assets to Debt Ratio: Meaning, Formula and Examples
• Proprietary Ratio: Meaning, Formula, Significance and Examples
• Activity Ratio: Meaning, Formula and Significance
• Trade Payable Turnover Ratio: Meaning, Formula, Significance and Examples
• Working Capital Turnover Ratio: Meaning, Formula, Significance and Examples
• Overall Profitability Ratio: Meaning, Formula, Significance, and Examples
• Gross Profit Ratio: Meaning, Formula, Significance and Examples
• Operating Ratio | Formula and Examples
• Operating Profit Ratio: Meaning, Formula, Significance and Examples
• Net Profit Ratio
• Return on Investment (ROI): Meaning, Formula, Significance and Illustrations
• Ratio Analysis Formula

Chapter 4: Cash Flow Statement

• What is a Cash Flow Statement?
• Cash Flow Statement: Objectives, Importance and Limitations
• Classification of Business Activities in Cash Flow: Operating, Investing and Financing Activities
• Cash Flow from Operating Activities
• Treatment of Special Items in Cash Flow Statement
• Treatment of Special Items in Cash Flow Statement-II
• Examples of Cash Flow from Operating Activities
• Cash Flow from Investing Activities
• Cash Flow from Financing Activities
• Cash Flow Statement: Two Examples

Part-B Chapter 1: Overview of Computerised Accounting System

• Sourcing of Accounting Software
• Computerised Accounting System
• Computerized Accounting System - Meaning, Features, Advantages and Disadvantages
• Difference between Manual and Computerised Accounting
• Difference between Management Information System (MIS) and Accounting Information System (AIS)
• Evolution and Features of Computerised Accounting

Components of Computer

Cbse previous year papers (2020).

• CBSE Class 12 Accountancy Solved Question Paper (Paper Code: 67/1/1, 2020)
• CBSE Class 12 Accountancy Solved Question Paper (Paper Code: 67/1/2, 2020)
• CBSE Class 12 Accountancy Solved Question Paper (Paper Code: 67/1/3, 2020)
• CBSE Class 12 Accountancy Solved Question (Paper-67/2/1-2020)
• CBSE Class 12 Accountancy Solved Question Paper-67/2/2
• CBSE Class 12 Accountancy Solved Question Paper (Paper Code: 67/2/3, 2020)
• CBSE Class 12 Accountancy Solved Question Paper (67/4/1, 2020)

A computer is an electronic device that accepts data, performs operations, displays results, and stores the data or results as needed. It is a combination of hardware and software resources that integrate together and provides various functionalities to the user. Hardware is the physical components of a computer like a processor, memory devices, monitor, keyboard, etc., while software is a set of programs or instructions that are required by the hardware resources to function properly. 

Components of a Computer

There are basically three important components of a computer:

• Central Processing Unit(CPU)
• Output Unit

1. Input Unit:

The input unit consists of input devices that are attached to the computer. These devices take input and convert it into binary language that the computer understands. Some of the common input devices are keyboard, mouse, joystick, scanner etc.

• The Input Unit is formed by attaching one or more input devices to a computer.
• A user input data and instructions through input devices such as a keyboard, mouse, etc.
• The input unit is used to provide data to the processor for further processing.

2. Central Processing Unit:

Once the information is entered into the computer by the input device, the processor processes it. The CPU is called the brain of the computer because it is the control centre of the computer. It first fetches instructions from memory and then interprets them so as to know what is to be done. If required, data is fetched from memory or input device. Thereafter CPU executes or performs the required computation, and then either stores the output or displays it on the output device. The CPU has three main components, which are responsible for different functions: Arithmetic Logic Unit (ALU), Control Unit (CU) and Memory registers

A. Arithmetic and Logic Unit (ALU): The ALU, as its name suggests performs mathematical calculations and takes logical decisions. Arithmetic calculations include addition, subtraction, multiplication and division. Logical decisions involve the comparison of two data items to see which one is larger or smaller or equal. 

• Arithmetic Logical Unit is the main component of the CPU
• It is the fundamental building block of the CPU.
• Arithmetic and Logical Unit is a digital circuit that is used to perform arithmetic and logical operations.

B. Control Unit: The Control unit coordinates and controls the data flow in and out of the CPU, and also controls all the operations of ALU, memory registers and also input/output units. It is also responsible for carrying out all the instructions stored in the program. It decodes the fetched instruction, interprets it and sends control signals to input/output devices until the required operation is done properly by ALU and memory.

• The Control Unit is a component of the central processing unit of a computer that directs the operation of the processor.
• It instructs the computer’s memory, arithmetic and logic unit, and input and output devices on how to respond to the processor’s instructions.
• In order to execute the instructions, the components of a computer receive signals from the control unit.
• It is also called the central nervous system or brain of the computer.

C. Memory Registers: A register is a temporary unit of memory in the CPU. These are used to store the data, which is directly used by the processor. Registers can be of different sizes(16 bit, 32 bit, 64 bit and so on) and each register inside the CPU has a specific function, like storing data, storing an instruction, storing address of a location in memory etc. The user registers can be used by an assembly language programmer for storing operands, intermediate results etc. Accumulator (ACC) is the main register in the ALU and contains one of the operands of an operation to be performed in the ALU.

Memory attached to the CPU is used for the storage of data and instructions, and is called internal memory The internal memory is divided into many storage locations, each of which can store data or instructions. Each memory location is of the same size and has an address. With the help of the address, the computer can read any memory location easily without having to search the entire memory. When a program is executed, its data is copied to the internal memory and stored in the memory till the end of the execution. The internal memory is also called the Primary memory or Main memory. This memory is also called RAM, i.e., Random Access Memory. The time of access of data is independent of its location in memory, therefore, this memory is also called Random Access memory (RAM).

• Memory Unit is the primary storage of the computer.
• It stores both data and instructions.
• Data and instructions are stored permanently in this unit so that they are available whenever required.

3. Output Unit : 

The output unit consists of output devices that are attached to the computer. It converts the binary data coming from the CPU to human understandable form. The common output devices are monitor, printer, plotter, etc.

• The output unit displays or prints the processed data in a user-friendly format.
• The output unit is formed by attaching the output devices of a computer.
• The output unit accepts the information from the CPU and displays it in a user-readable form.

Characteristics of a Computer

1. Speed: Computers can perform millions of calculations per second. The computation speed is extremely fast.

2. Accuracy: Because computers operate on pre-programmed software, there is no space for human error.

3. Diligence: They can perform complex and long calculations at the same time and with the same accuracy.

4. Versatile: Computers are designed to be versatile. They can carry out multiple operations at the same time.

5. Storage: Computers can store a large amount of data/ instructions in its memory, which can be retrieved at any point of time.

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Title: towards a technical debt for recommender system.

Abstract: Balancing the management of technical debt within recommender systems requires effectively juggling the introduction of new features with the ongoing maintenance and enhancement of the current system. Within the realm of recommender systems, technical debt encompasses the trade-offs and expedient choices made during the development and upkeep of the recommendation system, which could potentially have adverse effects on its long-term performance, scalability, and maintainability. In this vision paper, our objective is to kickstart a research direction regarding Technical Debt in Recommender Systems. We identified 15 potential factors, along with detailed explanations outlining why it is advisable to consider them.

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