Introduction to Computers

Today in this fast-moving world, human beings needs are growing, and so are these innovations.

The discovery of the wheel revolutionised the complete transport system. Similarly, the innovation of machines like computers has almost changed our lives. Today, with this electronic device, we can complete any work within seconds, which took hours to complete.

These days almost everything is done by computers. Computers are used in all sectors, schools, hospitals, offices, businesses, sale purchases, big projects, legal formalities, etc. almost every work involves computers.

Today, millions of people are working in the field of computer technology.

Let us know more about computers.

In this article, we shall know more about computers, characteristics of a computer, types and main parts of computers.

What is a Computer?

A computer is an electronic device that performs complex calculations, accepts data and gives the desired results.

The word ‘computer’ has been derived from the English word ‘compute’ that means ‘to calculate’.

Characteristics of a Computer

A computer carries out sequences of arithmetic or logical operations automatically.

The computer has several characteristics, listed below are a few of them:

  1. The computer works at a very fast speed.
  2. The computer always gives correct results.
  3. The computer performs every task efficiently and accurately.
  4. The computer can store a large amount of information in a very small space.
  5. The computer is an electronic device, which can work for a long time without getting tired.

Applications of Computers

The use of computers has brought a significant change in our lives. The computer is widely used in:

  1. Banking
  2. Transport
  3. Hospitals
  4. Education
  5. Agriculture
  6. Art
  7. Security
  8. Employment
  9. Entertainment
  10. Sports
  11. Business and Industry
  12. News communication
  13. Government offices
  14. Shops
  15. Science and Engineering

History of Computers

After the invention of many new technologies brought about a revolution in the lives of human beings. Similarly, the discovery of computers has also revolutionised the whole world.

Computers have evolved in five generations:

  • First, second, and the third generation computers were quite big, and their cost was also very high. An ordinary person could not think of buying them.
  • Later the fourth and fifth generation computers were invented, which were smaller than other third generation computers.
  • Along with the size of the computer, the working efficiency and utility also increased.
  • The cost decreased substantially.
  • Today, the computer is within reach of an ordinary person.

Types of Computers

Technologically, computers are divided into three types: Digital, Analog and Hybrid.

Today in India, most of us are using digital computers. Based on structure and work, digital computers are divided into four types:

Micro Computers

  • Microcomputers are smaller in size.
  • Desktop, Tablet and Laptop are examples of microcomputers.

Mini Computer

  • Minicomputers are bigger than microcomputers.
  • Their working efficiency is much higher than the microcomputers.
  • These computers are used in offices, ticket booking offices of railway and airways, defence establishments, etc.

Mainframe Computer

  • Mainframe computers are more significant than minicomputers.
  • Their working efficiency is much higher than the mini computer.
  • They are used in huge companies where many calculations and record-keeping are required.
  • These computers are used in large organizations, such as industries, censuses, consumer statistics and other large-scale transaction processing.


  • Supercomputers are the most significant size.
  • These computers are extremely powerful.
  • Supercomputers are used primarily for scientific and engineering work, which require exceedingly high-speed computations.
  • Supercomputers were used in applications related to national securities.
  • The Meteorological Departments use supercomputers to forecast daily weather information.
  • These computers are used in the aerospace, petroleum, and automotive industries.

Main Parts of a Computer

The main parts of a computer are- CPU, Monitor, Keyboard and the Mouse.

CPU – Central Processing Unit

CPU works as the heart and brain of the computer.

It helps in processing all the commands that the user gives.


It is an output device as it shows the processed information

The commands processed by the CPU are displayed on the monitor.


The keyboard is an input device

The keyboard is just like a typewriter.

Commands are given to the CPU by typing on the keyboard.


The mouse is an input device

The mouse helps to give commands by pressing on the icons visible on the monitor.

Precaution to be Taken while Working on Computers

There are a few essential precautions to be taken while working on computers.

Listed below are some of them:

  • Computers should be switched on and shut down properly.
  • Don’t keep eatables near the computers.
  • Protect the computer from dust and dampness.
  • When you finish your work, never leave your computer unattended. Switch it off when it is not in use.
  • Do use a UPS with the computer so that a sudden power failure does not cause loss of your work.

Frequently Asked Questions on Introduction to Computers


What is UPS?

UPS – Uninterrupted Power Supply. It helps computers to keep working even when the power goes off.


What are the steps to be followed to shut down the computer?

To shut down or switch off the computer, follow the below-given instructions:

  • Click on the ‘start’ button on the monitor screen.
  • You will get an option of ‘shut down.
  • Click on this option.
  • The computer will again try to confirm your action.
  • Again click on the option OK.
  • When the screen gets clear and the mouse and keyboard light switches off, switch off the UPS.
  • Finally, switch off the main power button.

What are the main parts of a computer?

A computer has mainly four parts:

  1. CPU
  2. Monitor
  3. Keyboard
  4. Mouse

What are the steps to be followed to switch on the computer?

To switch on the computer, follow the below-given instructions:

  1. At first press the main power switch.
  2. Next, switch on the UPS (Uninterrupted Power Supply) button.
  3. Next, switch on the CPU’s button.
  4. At last, the monitor’s button is switched on.
  5. Don’t hurry; wait till you see something on the desktop screen on the monitor.
  6. Now start working on the computer.

What are the types of computers?

Based on their structure and functions, computers can be divided into four types:

  1. Micro Computers
  2. Mini Computers
  3. Mainframe Computers
  4. Super Computers.

Stay tuned to BYJU’S, for more information on NIOS, syllabus, notes, along with its important questions and solutions.


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