Computer
In the simplest definition, a computer is an electronic device – a flexible machine that can manipulate data.
Computer is being used for tasks as adding up the supermarket bill, getting cash at an ATM, by writes, music composers, film producers, directors, poets, graphic illustrators and scholars of medieval history.
A computer is programmable i.e. the computer depends totally on the program, which the computer is using.
A program is a list of instructions, telling the computer ‘what to do.’
A computer’s hardware (the machine and its components) is designed to be as flexible as possible. By using computer programs, called software, one transforms this flexible hardware into a tool for a specific purpose. No matter which program a computer is using, the machine itself performs only four basic operations.
- Input: A computer accepts data that is provided by means of an input device, such as a keyboard
- Processing: A computer performs operations on the data to transform it in some way.
- Output: A computer produces output on a device, such as a printer or a monitor, that shows the results of processing operations.
- Storage: A computer stores the results of processing operations for future use.
This definition is often referred to as the IPOS cycle. The four steps of the IPOS cycle- input, processing, output, storage – do not have to occur in a rigid IPOS sequence. Under the direction of a program, a computer uses the steps of this process when needed and as often as needed. The use of a personal computer, a computer designed to meet an individual’s computing needs, illustrates these four basic computer operations. We use the keyboard for taking the input data. The computer’s internal circuitry processes the data. We see the results (output) on the computer’s monitor (The TV-like display). We can also store the results on the computer’s internal disk or on a removable disk.
The system unit contains the components with which the computer processes and stores the data. The keyboard and the mouse are input devices. The monitor displays the output. The printer prints the output.