GCSE Computing/Components of a Computer System

What you need to know
This topic introduces computer systems and provides a foundation for the remaining topics in this unit. Candidates should develop a mental model of a computer system which comprises hardware and software and in which: This model applies to the personal computer, but candidates should be aware of how it also applies to equipment which uses computer technology
 * data is input and converted into the computer’s internal representation by input devices
 * the data is processed
 * the results of the processing are converted from the computer’s internal representation and output by an output device
 * the data may be stored for later use or transmitted to another computer system while it is still in the computer’s internal representation.

Candidates should be able to
(a) define a computer system (b) describe the importance of computer systems in the modern world (c) explain the need for reliability in computer systems (d) explain the need for adherence to suitable professional standards in the development, use and maintenance of computer systems (e) explain the importance of ethical, environmental and legal considerations when creating computer systems.

Introduction
A complete Computer System can have many different components. What components are used will depend on what the computer system is designed to do. However all components can be divided in to two different types:
 * Hardware
 * Software

Hardware refers to any component that has a physical presence. If you can touch it then it is hardware. This can include things like the CPU, hard-drive, printer, mouse and so on. Software refers to computer programs which control how the hardware behaves. Some examples of software includes Operating System, word processors, databases, games and utilities.