HPSSC JOA IT – Introduction to Computer

Sstudyhub has started a series of the article where we will discuss how you can prepare for HPSSC JOA IT Exam. We will discuss each and every topic and after every topic, you can attempt the quiz which will help in analyzing your performance. Today, we will start from the basic topic which is Introduction to Computer.

Introduction to Computer

Computers play an important role in our life today and approx. every work depends on these computers. The computer word has been derived from the word compute which means to calculate. A computer Device is an electronic device which is used for performing arithmetic and logical operations. There can be a lot of definitions for the computer.

The computer is an electronic device which accepts input provided from users and then processes it and gives us the valid output. In today’s world, the computer is used for Office work, Defence, Home, Education, E-Commerce, School/Colleges etc. In every sector, computers are widely used.

Parts of Computer

The following are the main parts of the computer:-

  • CPU:- It is known as the brain of the computer.
  • Monitor:- Monitor is the device which displays the output.
  • Keyboard:- Keyboard is an Input Device which is used for providing the input.
  • Mouse:- Mouse is known as the pointing device which can be used for selecting and opening the different menu’s or options.
  • Printer:- It is an Output Device which can be used to print the Hard Copy of any document.
  • Speaker:- Speaker is also an Output Device which can be used to hear the sound. You can also use these speakers to listen to music and play games.
  • UPS:- UPS are used to provide Power supply to computers when there is no electricity. UPS stands for Uninterruptable Power Supply.


Computers provides us so many features but today we will discuss some of them.

  • The main feature of the computer is speed. You can perform any task within seconds. A Human will require years to perform any particular task but with computers, you can perform this task in seconds.
  • You can store a lot of information on the computer as it provides you with a high storage option.
  • Accuracy is also an important feature of computers. You can perform high accuracy tasks on these devices.
  • If you start performing a Job then it does not require further Human Intervention.
  • Multitasking is an important feature. With this feature, you can perform multiple tasks simultaneously without affecting the quality of the tasks.

Some Important Dates to Remember

  • Adding Machines in 1642 by Blaise Pascal.
  • Multiplying Machines in 1692 by Gottfried Leibniz.
  • Difference Engine in 1813 by Charles Babbage.
  • Arithrometer in 1862 by Charles Xavier Thomas.
  • Analytical Engine in 1863 by Charles Babbage.
  • Turing Machine in 1930 by Alan Turing.
  • ENIAC ( Electronic, Numbers, Integrated and Calculator ) in 1963 developed by John Mauchly, J. Presper Eckert.
  • In 1947, Transistors were invented by William Shockley, John Bardeen and Walter Brattain.
  • EDVAC ( Electronic Discrete Variable Automatic Computer ) by Maurice Wilkes and his team in 1949.
  • UNIVAC ( Universal Automatic Computer ) by John W. Mauchly in 1951.
  • COBOL was developed by Grace Hopper and it was the first programming language.
  • FORTRAN By John Backus in 1954.
  • 1st Micro Computer is developed by H. Edward Robert in 1975.
  • Apple Computer developed by Steven Jobs and Stephen Wozniak.
  • in 1996, Sergey Brin and Larry Page developed the Google Search Engine.
  • MS Windows 7 launched by Microsoft in 2009 and in 2015 Microsoft launched Windows 10.

Computer Generations

This is the most important topic of the chapter – Introduction to computer. You can expect 2 or 3 questions from this topic.

First Generation of Computer (1942-1955)

Vacuums Tubes are used in these types of computers and Magnetic tapes are used for external storage. Machine language is also introduced in this generation of computers.


Second Generation of Computer (1955-1964)

In the second generation of computers, computers are based on Transistors and Magnetic tapes are used for storing the data. The development of High Level Language started in this generation.

Eg:- IBM-1400, GE-635, UNIVAC 1108, Honeywell 400.

Third Generation of Computer (1964-1975)

In the third generation of computers, computers are based on IC (Integrated Circuits). Keyboards are introduced in this generation to input the data and High level Language is also introduced.

Eg:- IBM 3600, PDP-8, PDP-11.

Fourth Generation of Computer (1975-1989)

In the fourth generation of computers, computers are based on Very Large Scale Integrated (VLSI). In this generation, micro computer concept is introduced.

Eg:- IBM PC, VAX 9000 m CRAY 1, CRAY 2 etc.

Fifth Generation of Computer (1989-Present)

In the fifth generation of computers, Artificial Intelligence is introduced and these computer used Ultra Large Size Integration (ULSI).

Eg:- PARAM, IBM SP/2, Super Computers etc.

Summary of Introduction to Computer

  • Supercomputers are the fastest computers which can execute millions of instructions in a second. These computers are used for weather forecasting, Defence, Nuclear Energy Research etc.
  • Mainframe computers are capable of supporting hundreds of users simultaneously. These computers are used for banking applications, Railway reservations etc.
  • Mini Computers can also support hundreds of users simultaneously. These are less expensive than Mainframe computers and also smaller in Size. Mini Computers are more powerful than Personal Computers.
  • Microcomputers are the computers which store fewer data and are slower in speed among all other computers.
  • With the help of ethernet cable, you can connect two computers with each other.
  • First mechanical Computer is known as Analytical Engine.
  • Charles Babbage is the father of computers.
  • There are 1024 characters in ASCII Coding system.
  • In Windows XP, XP Stands for Experience.
  • First Electronic computer was developed by J.V. Atanasoff.
  • PDA ( Personal Digital Assistant) is also known as Palmtops.
  • IBM was founded by Thomas J. Watson.

MCQ Quiz based on Introduction to Computer

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