Hardware is the physical components of a computer, while the software is a collection of programs and related data to perform the computers desired function. The software can be edited while the hardware can not. There are four main groups of hardware; Those concerned with input, the central processing unit (CPU), storage hardware components and those concerned with output.
Input hardware devices are things such as keyboards, mice, scanners or an analogue to digital converter and are used to provide data and control signals to an information processing system.
Storage hardware can be either volatile or non-volatile memory. Volatile memory, or Random Access Memory (RAM), stores data while it is being manipulated and is synonymous with the working memory of the human mind.
This is the information which is lost on computer shutdown. For example, this word document I’m typing at the moment is stored on RAM until I save it. When I save this document (as I have just done) It is now stored on a form of non-volatile memory; the hard drive. Other forms of non-volatile memory include the read-only memory (ROM) where programs integral to the computer’s function are stored and storage devices such as CDs. ROM hardware also includes expansion cards such as graphics cards.
The Central Processing Unit (CPU) executes a sequence of stored information, or, programs.
Output Hardware is any hardware which is used to communicate the results of the computer to the outside world. Monitors, printers and speakers are all forms of output hardware.