Software
Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. Data software exists solely for its eventual use by other program software.
The term software was first used in this sense by John W. Tukey in 1957; colloquially, the term is often used to mean application software. In computer science and software engineering, computer software is all information processed by computer system, programs and data.
Computer software is often contrasted with computer hardware, which is the physical substrate on which software exists.
For other uses of the word software see Software (disambiguation).
Software varieties
Any modern general purpose computer (as opposed to an embedded system) has a number of layers of software performing a variety of tasks. These are often divided into three major categories:
- System software
- System software includes the basic input-output system (often described as firmware rather than software), device drivers, an operating system, and typically a graphical user interface which, in total, allow a user to interact with the computer and its peripherals (associated equipment). System software often comes bundled with the computer, and users may not realize that it exists.
- Application software
- Application software allows a user to accomplish one or more specific tasks, like office suites and video games. Application software is often purchased separately. Applications are what most people think of when they think of software.
- User software
- User software tailors systems to meet the users specific needs. User software include spreadsheet templates, word processor macros, scientific simulations, graphics and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.
Software in operation
Computer software has to be "loaded" into the computer's storage (or memory).
Once the software is loaded, the computer is able to operate. Computers operate by executing the software. This involves passing instructions from the application software, through the system software, to the hardware which ultimately receives the instruction as machine code. Each instruction causes the computer to carry out an operation -- moving data, carrying out a computation, or altering the flow of instructions.
Software creation
Software is created with programming languages and related utilities, which may come in several of the above forms: single programs like script interpreters, packages containing a compiler, linker, and other tools; and large suites (often called Integrated Development Environments) that include editors, debuggers, and other tools for multiple languages.
Software patents
The issue of software patents is very controversial, since while patents protect the ideas of "inventors", they are widely believed to hinder software development.
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