What is computer ? | Definition of Computer | Function of Computer

Today's world is an information-rich world and it has become a necessity for everyone to know about computers. 

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 use them when required.
• Processes the data and converts it into useful information.
• Generates the output
• Controls all the above four steps.
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Definition

A computer is an electronic data processing device which

• accepts and stores data input,
• processes the data input, and
• generates the output in a required format.

Advantages

The following list demonstrates the advantages of computers in today's arena.

High Speed

• A computer is a very fast device.
• It is capable of performing the calculation of a very large amount of data.
• The computer has units of speed in a microsecond, nanosecond, and even picosecond.
• It can perform millions of calculations in a few seconds as compared to the man who will spend many months doing the same task.

Accuracy

• In addition to being very fast, computers are very accurate.
• The calculations are 100% error-free.
• Computers perform all jobs with 100% accuracy provided that correct input has been given.

Storage Capability

• Memory is a very important characteristic of computers.
• A computer has much more storage capacity than human beings.
• It can store large amounts of data.
• It can store any type of data such as images, videos, text, audio, and many others.

Diligence

• Unlike human beings, a computer is free from monotony, tiredness, and lack of concentration.
• It can work continuously without any errors and boredom.
• It can do repeated work with the same speed and accuracy.

Versatility

• 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 problems related to various fields.
• At one instance, it may be solving a complex scientific problem, and the very next moment it may be playing a card game.

Reliability

• A computer is a reliable machine.
• Modern electronic components have long lives.
• Computers are designed to make maintenance easy.

Automation

• A computer is an automatic machine.
• Automation means the ability to perform a given task automatically.
• Once a program is given to a computer i.e., stored in computer memory, the program and instruction can control the program execution without human interaction.

Reduction in PaperWork

• The use of computers for data processing in an organization leads to a reduction in paperwork and results in speeding up a process.
• As data in electronic files can be retrieved as and when required, the problem of maintenance of a large number of paper files gets reduced.

Reduction in Cost

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

Disadvantages

The following list demonstrates the disadvantages of computers in today's arena

No I.Q

• A computer is a machine that has no intelligence to perform any task.
• Each instruction has to be given to the computer.
• A computer cannot take any decision on its own.

Dependency

• It functions as per a user’s instruction, so it is fully dependent on the human being

Environment

• The operating environment of the computer should be dust free and suitable.

No Feeling

• Computers have no feelings or emotions.
• It cannot make a judgment based on feeling, taste, experience, and knowledge, unlike a human being.
• COMPUTER TYPES

• PC (Personal Computer)

  A PC can be defined as a small, relatively inexpensive computer designed for an individual user. PCs are based on microprocessor technology that enables manufacturers to put an entire CPU on one chip. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. At home, the most popular use for personal computers is playing games and surfing the Internet.

  Although personal computers are designed as single-user systems, these systems are normally linked together to form a network. In terms of power, nowadays High-end models of the Macintosh and PC offer the same computing power and graphics capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and Dell.

• Workstation

  The workstation is a computer used for engineering applications (CAD/CAM), desktop publishing, software development, and other such types of applications that require a moderate amount of computing power and relatively high-quality graphics capabilities.
  Workstations generally come with a large, high-resolution graphics screen, a large amount of RAM, inbuilt network support, and a graphical user interface. Most workstations also have a mass storage device such as a disk drive, but a special type of workstation, called a diskless workstation, comes without a disk drive.
  Common operating systems for workstations are UNIX and Windows NT. Like PC, Workstations are also single-user computers like PC but are typically linked together to form a local area network, although they can also be used as stand-alone systems.

• Minicomputer

  It is a midsize multi-processing system capable of supporting up to 250 users simultaneously.

• Mainframe

  The mainframe is very large in size and is an expensive computer capable of supporting hundreds or even thousands of users simultaneously. Mainframe executes many programs concurrently and supports much simultaneous execution of programs