Computer - Overview


Today's world is an information-rich world and it has become a necessity for everyone to know about computers. Purpose of this tutorial is to introduce you about computer systems and its fundamentals.

Functionalities of a computer

Any digital computer carries out five functions in gross terms:

  • Takes data as input.

  • Stores the data/instructions in its memory and can use them when required.

  • Processes the data and converts it into useful information.

  • Outputs the information.

  • Controls all the above four steps.



Computer System is an electronic data processing device, which does the following:

  • Accept and store an input data.

  • Process the data input.

  • And output the processed data in required format.


Following list demonstrates the advantages of Computers in today's arena.

High Speed

  • Computer is a very fast device.

  • It is capable of performing addition of very big data.

  • The computer has units of speed in microsecond, nanosecond and even the picosecond.

  • It can perform millions of calculations in a few seconds as compared to man, who can spend many months for doing the same task.


  • In addition to being very fast, computers are very accurate.

  • The computer has performed calculations 100% error-free.

  • Computers perform all jobs with 100% accuracy.

Storage Capability

  • Memory is a very important characteristic of computers.

  • The computer has much more storage capacity than human beings.

  • It can store large amount of data.

  • It can store any type of data such as images, videos, text, audio and any other type.


  • Unlike human beings, a computer is free from monotony, tiredness and lack of concentration.

  • It can work continuously without creating any error and boredom.

  • It can do repeated work with same speed and accuracy.


  • A computer is a very versatile machine.

  • A computer is very flexible in performing the jobs to be done.

  • This machine can be used to solve the problems relating to various different fields.

  • At one instant, it may be solving a complex scientific problem and the very next moment it may be playing a card game.


  • A computer is a reliable machine.

  • Modern electronic components have failure-free long lives.

  • Computers are designed to make maintenance easy.


  • Computer is an automatic machine.

  • Automation means ability to perform the task automatically.

  • Once a program is given to computer, i.e., stored in computer memory, the program and instructions can control the program execution without human interaction.

Reduction in Paper Work

  • The use of computers for data processing in an organization leads to reduction in paper work and speeds up the process.

  • As data in electronic files can be retrieved as and when required, the problem of maintenance of large number of files gets reduced.

Reduction in Cost

  • Though the initial investment for installing a computer is high but it substantially reduces the cost of each of its transaction.


Following list demonstrates the disadvantages of Computers in today's arena.


  • A computer is a machine and has no intelligence of its own to perform any task.

  • Each and every instruction has to be given to the computer.

  • A computer can not take any decision on its own.


  • It can perform function as instructed by user, so it is fully dependent on human being.


  • The operating environment of computer should be dust-free and suitable to it.

No Feeling

  • Computer has no feeling or emotions.

  • It cannot make judgement based on feeling, taste, experience and knowledge unlike a human being.