In computer technology, a default (noun, pronounced dee-FAWLT ) is a predesigned value or setting that is used by a computer program when a value or setting is not specified by the program user. The program user can be either an interactive user of a graphical user interface or command line interface, or a programmer using an application program interface . When the program receives a request from an interactive user or another program, it looks at the information that has been passed to it. If a particular item of information is not specified in the information that is passed, the program uses the default value that was defined for that item when the program was written. In designing a program, each default is usually preestablished as the value or setting that most users would probably choose. This keeps the interface simpler for the interface user and means that less information has to be passed and examined during each program request.
To the program requestor, to default (verb) is to intentionally or accidentally allow the preestablished value or setting for an item to be used by the program. The program is said to default when it uses a default value or setting.
Default (adjective) pertains to something that is used when something else is not supplied or specified. For example, a default printer is a type of printer that is assumed to be connected to a computer unless the computer user specifies another type that is actually connected.