<networking> 1. A lasting connection between a user (or user
	agent) and a {peer}, typically a {server}, usually involving
	the exchange of many packets between the user's computer and
	the server.  A session is typically implemented as a layer in
	a network {protocol} (e.g. {telnet}, {FTP}).

	In the case of protocols where there is no concept of a
	session layer (e.g. {UDP}) or where sessions at the {session
	layer} are generally very short-lived (e.g. {HTTP}), {virtual}
	sessions are implemented by having each exchange between the
	user and the remote host include some form of {cookie} which
	stores state (e.g. a unique session ID, information about the
	user's preferences or authorisation level, etc.).

	See also {login}.

	2. A lasting connection using the {session layer} of a
	networking protocol.

	(1997-08-03)

<data, data processing, jargon> /day't*/ (Or "raw data")
	Numbers, {characters}, {images}, or other method of recording,
	in a form which can be assessed by a human or (especially)
	input into a {computer}, stored and {processed} there, or
	transmitted on some {digital channel}.  Computers nearly
	always represent data in {binary}.

	Data on its own has no meaning, only when interpreted by some
	kind of {data processing system} does it take on meaning and
	become {information}.

	People or computers can find patterns in data to perceive
	information, and information can be used to enhance
	{knowledge}.  Since knowledge is prerequisite to wisdom, we
	always want more data and information.  But, as modern
	societies verge on {information overload}, we especially need
	better ways to find patterns.

	1234567.89 is data.

	"Your bank balance has jumped 8087% to $1234567.89" is
	information.

	"Nobody owes me that much money" is knowledge.

	"I'd better talk to the bank before I spend it, because of
	what has happened to other people" is wisdom.

	(1999-04-30)

[probably from "main store"] In some varieties of Commonwealth
	hackish, the preferred synonym for {core}.  Thus, "bringing a
	program into store" means not that one is returning
	shrink-wrapped software but that a program is being {swap}ped
	in.

	[{Jargon File}]

1. A program which provides some service to other ({client})
	programs.  The connection between client and server is
	normally by means of {message passing}, often over a
	{network}, and uses some {protocol} to encode the client's
	requests and the server's responses.  The server may run
	continuously (as a {daemon}), waiting for requests to arrive
	or it may be invoked by some higher level daemon which
	controls a number of specific servers ({inetd} on {Unix}).

	There are many servers associated with the {Internet}, such as
	those for {HTTP}, {Network File System}, {Network Information
	Service} (NIS), {Domain Name System} (DNS), {FTP}, {news},
	{finger}, {Network Time Protocol}.  On Unix, a long list can
	be found in /etc/services or in the {NIS} database "services".
	See {client-server}.

	2. A computer which provides some service for other computers
	connected to it via a network.  The most common example is a
	{file server} which has a local disk and services requests
	from remote clients to read and write files on that disk,
	often using {Sun}'s {Network File System} (NFS) {protocol} or
	{Novell Netware} on {PCs}.  Another common example is a {web
	server}.

	[{Jargon File}]

	(2003-12-29)

To produce something according to an {algorithm} or program or
	set of rules, or as a (possibly unintended) {side effect} of
	the execution of an algorithm or program.

	The opposite of {parse}.

	[{Jargon File}]

	(1995-06-15)

Bourne Again SHell.  {GNU}'s {command interpreter} for {Unix}.
	Bash is a {Posix}-compatible {shell} with full {Bourne shell}
	syntax, and some {C shell} commands built in.  The Bourne
	Again Shell supports {Emacs}-style command-line editing, job
	control, functions, and on-line help.  Written by Brian Fox of
	{UCSB}.

	The latest version is 1.14.1.  It includes a {yacc} parser,
	the interpreter and documentation.

	{(ftp://ftp.gnu.org/bash-1.14.1.tar.gz)} or from a
	{GNU archive site}.  E-mail: <bug-bash@gnu.org>.
	{Usenet} newsgroup: {news:gnu.bash.bug}.

	(1994-07-15)

<programming> (Or "computer program", "program", "code") The
	instructions executed by a computer, as opposed to the
	physical device on which they run (the "{hardware}").

	The term was coined by the eminent statistician, {John Tukey}.

	Programs stored on {non-volatile storage} built from
	{integrated circuits} (e.g. {ROM} or {PROM}) are usually
	called {firmware}.

	Software can be split into two main types - {system software}
	and application software or {application programs}.  System
	software is any software required to support the production or
	execution of application programs but which is not specific to
	any particular application.  Examples of system software would
	include the {operating system}, {compilers}, editors and
	sorting programs.

	Examples of application programs would include an accounts
	package or a {CAD} program.  Other broad classes of
	application software include {real-time} software, {business
	software}, scientific and engineering software, {embedded
	software}, personal computer software and {artificial
	intelligence} software.

	Software includes both {source code} written by humans and
	executable {machine code} produced by {assemblers} or
	{compilers}.  It does not usually include the data processed
	by programs unless this is in a format such as {multimedia}
	which depends on the use of computers for its presentation.
	This distinction becomes unclear in cases such as {spread
	sheets} which can contain both instructions (formulae and
	{macros}) and data.  There are also various intermediate
	compiled or {semi-compiled}, forms of software such as
	{library} files and {byte-code}.

	Some claim that {documentation} (both paper and electronic) is
	also software.  Others go further and define software to be
	programs plus documentation though this does not correspond
	with common usage.

	The noun "program" describes a single, complete and
	more-or-less self-contained list of instructions, often stored
	in a single {file}, whereas "code" and "software" are
	uncountable nouns describing some number of instructions which
	may constitute one or more programs or part thereof.  Most
	programs, however, rely heavily on various kinds of {operating
	system} software for their execution.  The nounds "code" and
	"software" both refer to the same thing but "code" tends to
	suggest an interest in the implementation details whereas
	"software" is more of a user's term.

	(2002-07-21)

After-sale handholding; something many software vendors
	promise but few deliver.  To hackers, most support people are
	useless - because by the time a hacker calls support he or she
	will usually know the software and the relevant manuals better
	than the support people (sadly, this is *not* a joke or
	exaggeration).  A hacker's idea of "support" is a tte--tte
	or exchange of {electronic mail} with the software's designer.

	[{Jargon File}]

	(1995-02-15)

1. <mathematics> In the theory of functions, the set of
	argument values for which a {function} is defined.

	See {domain theory}.

	2. <networking> A group of computers whose {hostnames} share a
	common suffix, the "domain name".  The last component of this
	is the {top-level domain}.

	See {administrative domain}, {Domain Name System}, {fully
	qualified domain name}.

	3. {Distributed Operating Multi Access Interactive Network}.

	4. <programming> A specific phase of the {software life cycle}
	in which a developer works.  Domains define developers' and
	users' areas of responsibility and the scope of possible
	relationships between products.

	5. The subject or market in which a piece of software is
	designed to work.

	(1997-12-26)

1. To prepare to read or write a file.  This usually involves
	checking whether the file already exists and that the user has
	the necessary authorisation to read or write it.  The result
	of a successful open is usually some kind of {capability}
	(e.g. a {Unix} {file descriptor}) - a token that the user
	passes back to the system in order to access the file without
	further checks and finally to close the file.

	2. Abbreviation for "open (or left) parenthesis" - used when
	necessary to eliminate oral ambiguity.  To read aloud the LISP
	form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun
	foo, open eks close, open, plus eks one, close close."

	3. Non-proprietary.  An open {standard} is one which can be
	used without payment.

	[{Jargon File}]

	(1995-01-31)