A computer is an electronic machine that is designed to accept data and instructions store the data and instructions, process the data according to the instructions to produce desired results.

Data

Is defined as facts relating to people, place, events or things, which can be represented using numbers and letters. Eg: name, address, age etc…

Characteristics of computer

• Speed

A computer works with much higher speed and accuracy compared to humans while performing mathematical calculations.

• Accuracy

Computers perform calculations with 100% accuracy. Errors may occur due to data inconsistency or inaccuracy.

• Diligence

A computer can perform millions of tasks or calculations with the same consistency and accuracy. It doesn’t feel any fatigue or lack of concentration. Its memory also makes it superior to that of human beings.

• Versatility

Versatility refers to the capability of a computer to perform different kinds of works with same accuracy and efficiency.

• Reliability

A computer is reliable as it gives consistent result for similar set of data i.e., if we give same set of input any number of times, we will get the same result.

• High storage capacity

The computer has an in built memory where it can store large amount of data.

• No I.Q

It has no intelligence of its own. It can only perform tasks that a human can

• No feelings

It does not have feelings or emotion, so the instruction given to them in the form of programs that are written by us

The Types of Computer:

Computers can be generally classified by size and power as follows, though there is considerable overlap:

• Personal computer: A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.
• Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.
• Minicomputer: A multi-user computer capable of supporting from 10 to hundreds of users simultaneously.
• Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
• Supercomputer: An extremely fast computer that can perform hundreds of millions of instructions per second.

The Applications of Computers:

Computers are now being used in each and every field of science, engineering and technology. On an average almost everyday an organization or a company is being computerized. Computers are being used in Banks, Transport, Finance, Factories and many other organizations.

1. Computers are gaining growing importance from bank professionals. Here computerized Account keeping is done with all entries of a customer Account is being stored in a Computer’s memory instead of maintaining bulky ledgers with heavy pages.
2. Weather Forecasting

Weather prediction involves continuous evaluating of astrological equations and expressions of higher degree.

1. Computers are used in Simulation and graphics applications. Computers are used in Animation and cartoon films preparation . Using computer’s graphics Pilots cabin in an Aircraft is simulated such that a trainee pilot sitting in a computer lab or simulated pilots cabin on the ground itself, should get feel of flying in air, landing and take-off of the Aircraft from the Airport.
2. Computers are now becoming national & international communication agents. Computers of a particular area that is within a campus or university can be inter connected to have local area network. Thus information store in one computer can be shade by other interconnected computers.
3. Computers are being used in Railway ticket reservation. Computerized counters keep track the train number & other details.
4. Computers are used extensively in business data processing to maintain the account of stock, to reorder the goods etc. Payroll is an important data processing application of computers.

Computers are extensively used in military application. Military war fare  had proven effective use of computers in guiding the missiles