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A computer system

A computer system is one that is able to take a set of inputs, process them and create a set of outputs. This is done by a combination of hardware and software.

The computer system has one or more inputs to provide data. This data is then processed in some way. The outcome of the processing is sent to an output or it may be stored until some event happens to cause it to be output.

A program is a set of instructions of what needs to be done.

Computer input

The role of an input in a computer system is to provide data for further processing.

An input consists of data or commands that are entered using and input device such as a scanner or a bar-code reader.

The input data is converted into digital data that can be dealt with by the computer.

Keyboard - user presses a key. An electronic chip sense the key press and produces a digital code to represent the meaning of the key.

Mouse - User slides the mouse around. This movement is picked up by a sensor inside the mouse and digital data is sent as a result

Touch screen - User makes gestures on the surface of the screen or slides their finger along it. Sensors behind the screen pick up the action and converts them into digital data.

Microphone - The microphone system picks up sound and converts it into digital data.

Computer processing

Processing is the stage where the input data is manipulated in order to produce meaningful information.

Processing can include a number of stages including sorting, searching, calculations and graphing.

Examples of processing:

-Searching sales data to find which products have sold the most

-Sorting a list into alphabetic order

-After a bar code has been scanned(input) retrieving the price of the item from the database and using it to calculate the customers bill.

Computer output