3. Hardware

A computer system is a combination of hardware and software.

Hardware is the physical components that make up a computer. A good rule of thumb is that if you can touch it, it's hardware. If you can't, it's probably software.

Examples of hardware that you might find as part of a computer system are:-

• The CPU
• Hard disks
• Cables
• Monitors
• Keyboards
• Barcode readers

and many more.

Computer hardware doesn't do anything by itself. It must be given instructions. The instructions are set out by the computer's "software", which are programs written by developers or the users themselves.

For example, for a computer to use a monitor, the relevant software driver has to be installed in the operating system. The driver is supplied by the monitor manufacturer.