2. 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 diagram below shows you the idea of a computer system in its most basic form

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.

For processing to take place, there needs to be a set of instructions of what needs to be done. This set of instructions is called a program.

This system is called a stored-program computer.

The beauty of this type of computer system is that it is flexible - the machine performs a different task by simply loading a different program from storage.