Computer software (often called just software) is a set of instructions and associated documentation that tells a computer what to do or how to perform a task or it can mean all the software on a computer, including the applications and the operating system. Applications are programs that do a specific thing, such as a game or a word processor. The operating system (Mac OS, Microsoft Windows, Linux, etc.) is software that helps the applications run, and controls the display and the keyboard.
The word software was first used in the late 1960s to show the difference from computer hardware, which are the parts of a machine that can be seen and touched. Software is the instructions that the computer follows. Before compact discs (CDs) or Internet downloads, software came on various computer data storage media like paper punch cards, magnetic discs or magnetic tape.
If you compare computers to music and musical instruments you can think of hardware as being the instruments and software being the musical notes.
The word firmware is sometimes used to describe a style of software that is made specially for a particular type of computer (or other electronic device) and is usually stored on a Flash memory or ROM chip in the computer. Firmware usually refers to a piece of software that directly controls a piece of hardware, for example the firmware for a CD drive or the firmware for a modem.
Computer software can be put into categories based on common function, type, or field of use. There are three broad classifications:
- Application software are the computer programs for performing user tasks such as word processing and web browsers.
- System software is used to start and run computer systems and networks. This includes operating systems.
- Computer programming tools (also known as development software) are used to create application and system software. This is done by translating and combining computer program source code and libraries into executable RAMs. These include compilers and linkers.