<programming> A computer system or process that requests a
	service of another computer system or process (a "{server}")
	using some kind of {protocol} and accepts the server's
	responses.  A client is part of a {client-server} software
	architecture.

	For example, a {workstation} requesting the contents of a file
	from a {file server} is a client of the file server.

	(1997-10-27)

<process> The approach that engineering (and some other)
	disciplines use to specify how to create or do something.  A
	successful design must satisfies a (perhaps informal)
	{functional specification} (do what it was designed to do);
	conforms to the limitations of the target medium (it is
	possible to implement); meets implicit or explicit
	requirements on performance and resource usage (it is
	efficient enough).

	A design may also have to satisfy restrictions on the design
	process itself, such as its length or cost, or the tools
	available for doing the design.

	In the {software life-cycle}, design follows {requirements
	analysis} and is followed by implementation.

	["Object-Oriented Analysis and Design with Applications", 2nd
	ed., Grady Booch].

	(1996-12-08)

See {tuple}.

<character> (Or "ctrl", "^") One (or a pair) of {modifier
	keys} found on all modern {keyboards}.  If the control key is
	held down while pressing and releasing certain other keys then
	a "{control character}" is generated, e.g. holding control and
	hitting "A" generates control-A ({ASCII} code 1).  The ASCII
	code for the control character is generally 64 less than that
	for the unmodified character.

	The control key does not generate any character on its own but
	most modern keyboards and {operating systems} allow a program
	to tell whether each of the individual keys on the keyboard
	(including modifier keys) is pressed at any time.

	Control characters mostly have some kind of "non-printing"
	effect on the output such as ringing the bell (Control-G) or
	advancing to the next line (Control-J).  Most have alternative
	names suggesting these functions (Bell, Line Feed, etc.).

	See {ASCII character table}.

	(1997-07-10)

The process of analysis, design, coding and testing software.

1. <data, graphics> Data representing a two-dimensional scene.
	A digital image is composed of {pixels} arranged in a
	rectangular array with a certain height and width.  Each pixel
	may consist of one or more {bits} of information, representing
	the brightness of the image at that point and possibly
	including colour information encoded as {RGB} triples.

	{Images} are usually taken from the real world via a {digital
	camera}, {frame grabber}, or {scanner}; or they may be
	generated by computer, e.g. by {ray tracing} software.

	See also {image formats}, {image processing}.

	(1994-10-21)

	2. <mathematics> The image (or range) of a {function} is the
	set of values obtained by applying the function to all
	elements of its {domain}.  So, if f : D -> C then the set f(D)
	= \{ f(d) | d in D \} is the image of D under f.  The image is
	a subset of C, the {codomain}.

	(2000-01-19)

<messaging> (verb) To send (a copy of) an {electronic mail}
	message that you have received on to one or more other
	{addressees}.  Most e-mail systems can be configured to do
	this automatically to all or certain messages, e.g. {Unix}
	{sendmail} looks for a ".forward" file in the recipient's
	{home directory}.

	A {mailing list} server (or "{mail exploder}") is designed to
	forward messages automatically to lists of people.

	{Unix manual page}: aliases(5).

	(2000-03-22)

<standard, body> (ISO) A voluntary, nontreaty organisation
	founded in 1946, responsible for creating international
	{standards} in many areas, including computers and
	communications.  Its members are the national standards
	organisations of 89 countries, including the {American
	National Standards Institute}.

	ISO produced the {OSI} seven layer model for network
	architecture.

	The term "ISO" is not actually an acronym for anything.  It is
	a pun on the Greek prefix "iso-", meaning "same".  Some ISO
	documents say ISO is not an acronym even though it is an
	anagram of the initials of the organisation's name.

	{Home (http://www.iso.ch/)}.

	(1999-06-22)

<software> Instructions for a computer in some programming
	language, often {machine language}.  The word "code" is often
	used to distinguish instructions from {data} (e.g. "The code
	is marked 'read-only'") whereas "{software}" is used in
	contrast with "{hardware}" and may consist of more than just
	code.

	(2000-04-08)