| | Hardware : Introduction | 
|
|
A computer system will input, process and then output data. A computer system consists of the computer and other hardware devices that are used with the computer. A hardware device is an electronic or electro-mechanical device such as a keyboard or monitor which forms part of a computer system.
The diagrams below show one simple and one more complicated computer system.
The devices connected to the computer can be divided up into three different classes :
| Input Devices | An input device takes data from the outside world and sends it to the computer. e.g. keyboard, mouse. |
| Output Devices | An output device takes data from the computer and converts this into information in a form which is normally understandable by humans. e.g. printer, VDU. |
| Input / Output (I/O) Devices | Data flows in both directions between the computer and an I/O device. Most I/O devices are used for storage e.g. hard disk drive or communications e.g. modem. Others include MIDI keyboards. |
Some devices such as disk drives, modems and CD-ROM drives are now built into the same box as the computer. This helps to keep computers tidy. Devices connected to a computer are often known as peripherals.
Computer hardware is not very useful by itself. The hardware needs to be told what to do. A computer program contains instructions to tell the computer hardware what to do to carry out a particular task. Computer programs are produced using a programming language. Computer programs are also known as software. The most important piece of computer software that a computer system must have to function is an operating system. Other useful pieces of computer software include word processors, spreadsheets and databases.
GCSE ICT Companion 04 - (C) P Meakin 2004