<electronics> The quantity of {charge} per unit time, measured
	in Amperes (Amps, A).  By historical convention, the sign of
	current is positive for currents flowing from positive to
	negative {potential}, but experience indicates that electrons
	are negatively charged and flow in the opposite direction.

	(1995-10-05)

<World-Wide Web> (Or "website") Any computer on the
	{Internet} running a {World-Wide Web} {server} process.  A
	particular website is usually identified by the {hostname}
	part of a {URL}.  Multiple hostnames may actually map to the
	same computer in which case they are known as "{virtual
	servers}".

	(2005-07-12)

1. <programming, convention> /bar/ The second {metasyntactic
	variable}, after {foo} and before {baz}.  E.g. "Suppose
	function FOO calls functions BAR..."

	2. Often appended to {foo} to produce {foobar}.

	[{Jargon File}]

	(1995-03-07)

1. <database, information science> A user's (or {agent}'s)
	request for information, generally as a formal request to a
	{database} or {search engine}.

	{SQL} is the most common {database query language}.

	2. <character> {question mark}.

	(1997-04-09)

<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)

1. <hardware> An electrical conductor.  For distances larger
	than a breadbox, a single line may consist of two electrical
	conductors in twisted, parallel, or concentric arrangement
	used to transport one logical signal.

	By extension, a (usually physical) medium such as an {optical
	fibre} which carries a signal.

	(1995-09-29)

<mathematics, data> The {ancestor} {node} in a {tree} that
	points to the current node (one of its child nodes).

	(2005-09-15)

<operating system> A list from which the user may select an
	operation to be performed.  This is often done with a {mouse}
	or other pointing device under a {graphical user interface}
	but may also be controlled from the keyboard.

	Menus are very convenient for beginners because they show what
	commands are available and make experimentating with a new
	program easy, often reducing the need for user documentation.
	Experienced users however, often prefer keyboard commands,
	especially for frequently user operations, because they are
	faster to use.  In situations such as text entry where the
	keyboard must be used anyway, having to move your hand to the
	mouse to invoke a menu operation is slow.

	There are many different ways of presenting menus but the most
	common are the {menu bar} (with {pull-down menus}) and the
	{context-sensitive menu}.

	The term "menu" tends to be reserved for a list of actions or
	global options, whereas a "{list box}" or other graphical
	{widget} might present any kind of choice.

	See also {menuitis}.

	(1994-12-02)

<character> "=", {ASCII} character 61.

	Common names: {ITU-T}: equals; gets; takes.  Rare:
	quadrathorpe; {INTERCAL}: half-mesh.

	Equals is used in many languages as the {assignment} operator
	though earlier languages used ":=" ("becomes equal to") to
	avoid upsetting mathematicians with statements such as "x =
	x+1".  It is also used in compounds such as "<=", ">=", "==",
	"/=", "!=" for various comparison operators and in {C}'s "+=",
	"*=" etc. which mimic the {primitive} operations of
	{two-address code}.

	(1995-03-29)

<programming> A sequence of {instructions} that the
	{processor} repeats, either until some condition is met, or
	indefinitely.

	In an {structured language} (e.g. {C}, {Pascal}, {BASIC}, or
	{Fortran}), a loop is usually achieved with {for loop}, {while
	loop} or {repeat loop} constructs.

	In other languages these constructs may be synthesised with a
	{jump} ({assembly language}) or a {GOTO} (early Fortran or
	BASIC).

	(1999-05-06)

<architecture> {Data} transferred from a computer system to
	the outside world via some kind of {output device}.

	Opposite: {input}.

	(1997-04-28)

<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)

1. <architecture> {cache hit}.

	2. <World-Wide Web> A request to a {web server} from a {web
	browser} or other {client} (e.g. a {robot}).

	The number of hits on a server may be important for
	determining advertising revenue.

	In the course of loading a single {web page}, a browser may
	hit a web server many times e.g. to retrieve the page itself
	and each {image} on the page.  In contrast, caching by
	browsers and {web proxies} reduces the number of hits on the
	server because some requests are satisfied from the cache.

	3. <jargon> To press and release a key on the keyboard.  Some
	prefer the less aggressive "tap".

	(2000-02-20)

To perform {recursion}.

<jargon> A {marketroid} term for something he wants to sell
	you without bothering you with the often dizzying distinctions
	between {hardware}, {software}, {services}, {applications},
	{file formats}, companies, brand names and {operating
	systems}.

	"{Flash} is a perfect image-streaming solution."  "What is
	it?"  "Um...  about a thousand dollars."

	See also: {technology}.

	(1998-07-07)

<data> A data structure holding many values, possibly of
	different types, which is usually accessed sequentially,
	working from the head to the end of the tail - an "ordered
	list".  This contrasts with a (one-dimensional) {array}, any
	element of which can be accessed equally quickly.

	Lists are often stored using a cell and pointer arrangement
	where each value is stored in a cell along with an associated
	pointer to the next cell.  A special pointer, e.g. zero, marks
	the end of the list.  This is known as a (singly) "linked
	list".  A doubly linked list has pointers from each cell to
	both next and previous cells.

	An unordered list is a {set}.

	(1998-11-12)