Initialization is the process of locating and using the defined values for variable data that is used by a computer program. For example, an operating system or application program is installed with default or user-specified values that determine certain aspects of how the system or program is to function. Typically, these values are stored in initialization files (in Windows, these can be identified as files with an INI suffix). When the operating system or an application program is first loaded into memory, a part of the program performs initialization - that is, it looks in the initialization files, finds definite values to substitute for variable values, and acts accordingly. For example, the desktop appearance and application programs that are to be started along with the operating system are identified and loaded.
The process of the user specifying initialization values is sometimes called configuration .