software: is Software is a generic term organized collections of computer data instructions, into two major categories system software that provides the basic non task-specific functions of the computer and application software which is used by users to accomplish specific tasks. system software manage and control the hardware components of a computer system that the user see the hardware functional unit with it. an application software use as a typing image viewer,sharing data with microsoft office word spreadsheet. Unit of Measurements. Storage measurements. Speed measurement.