<programming, operating system> (Or "application", "app") A
	complete, self-contained program that performs a specific
	function directly for the user.  This is in contrast to system
	software such as the {operating system} {kernel}, {server}
	processes and libraries which exists to support application
	programs.

	Editors for various kinds of documents, {spreadsheets}, and
	text formatters are common examples of applications.  Network
	applications include clients such as those for {FTP},
	{electronic mail}, {telnet} and {WWW}.

	The term is used fairly loosely, for instance, some might say
	that a client and server together form a distributed
	application, others might argue that editors and compilers
	were not applications but tools for building applications.

	One distinction between an application program and the
	operating system is that applications always run in "user
	mode" (or "non-privileged mode"), while operating systems and
	related utilities may run in "supervisor mode" (or "privileged
	mode").

	The term may also be used to distinguish programs which
	communicate via a {graphical user interface} from those which
	are executed from the {command line}.

	(1994-11-28)

<operating system, programming> The process of carrying out
	the {instructions} in a computer program by a computer.

	See also {dry run}.

	(1996-05-13)

1. The {supervisor} program or {operating system} on a
	computer.

	2. The entire computer system, including input/output devices,
	the {supervisor} program or {operating system} and possibly
	other {software}.

	3. Any large program.

	4. Any method or {algorithm}.

	[{Jargon File}]

<jargon> Different systems (e.g., {programs}, {file formats},
	{protocols}, even {programming languages}) that can work
	together or exchange data are said to be compatible.

	See also {backward compatible}, {forward compatible}.

	(1998-01-15)

1. <networking> {e-mail address}.

	2. <networking> {Internet address}.

	3. <networking> {MAC address}.

	4. <storage, programming> An unsigned integer used to select
	one fundamental element of storage, usually known as a {word}
	from a computer's {main memory} or other storage device.  The
	{CPU} outputs addresses on its {address bus} which may be
	connected to an {address decoder}, {cache controller}, {memory
	management unit}, and other devices.

	While from a hardware point of view an address is indeed an
	integer most {strongly typed} programming languages disallow
	mixing integers and addresses, and indeed addresses of
	different data types.  This is a fine example for {syntactic
	salt}: the compiler could work without it but makes writing
	bad programs more difficult.

	(1997-07-01)

<storage> 1. {magnetic disk}.

	2. {compact disc}.

	3. {optical disk}.

	Note: the american spelling, "disk", is normal for most
	computer disks whereas "compact disc", having come to
	computers via the audio world, is correctly spelled with a
	"c", indeed, this spelling is part of the CD standard.

	(1995-07-30)

<networking> Hardware and software data communication systems.

	The {OSI} seven layer model attempts to provide a way of
	partitioning any computer network into independent modules
	from the lowest (physical) layer to the highest (application)
	layer.  Many different specifications exist at each of these
	layers.

	Networks are often also classified according to their
	geographical extent: {local area network} (LAN), {metropolitan
	area network} (MAN), {wide area network} (WAN) and also
	according to the {protocols} used.

	See {BITNET}, {Ethernet}, {Internet}, {Novell}, {PSTN},
	{network, the}.

	[Tanenbaum, A., "Computer Networks; 2nd ed.", Prentice Hall,
	Englewood Cliffs, NJ, 1989.]

	(1995-03-10)