The term black box has a number of meanings:

Black box vs. white box

Black box is technical jargon for a device or system or object when it is viewed primarily in terms of its input and output characteristics. Almost anything might occasionally be referred to as a black box, e.g., a transistor, the Internet. Some other common uses are:

• In electronics, a sealed piece of replaceable equipment—see line-replaceable unit.
• In computer programming and software engineering, black box testing is used to check that the output of a program is as expected given certain inputs. The term black box is used because the actual program being executed is not examined.
• In computing in general, a "black box program" is one where the user cannot see its inner workings (i.e.: is a closed source program)
• A limiting case in mathematical modelling.
• For applications in philosophy and psychology, see black box theory and behaviorism.

The opposite of this sort of black box has been called white box, glass box, or clear box.

Black box in avionics

In aircraft and avionics, the flight data recorders and cockpit voice recorders, that record aircraft and pilot behavior, and cockpit sounds, in order to analyze accidents are called black boxes by the news media; though they are now bright orange in colour, they were black when originally introduced, and the name stuck. Same name applies to similar devices now available to record data in motor vehicles.

Black box (game)

Black Box is a board and computer game.

Black Box (group)

Black Box was a music group popular in the early 1990s

Black Box Recorder

Black Box Recorder was a music group, popular in the early 2000s.

Black box in literature

In literature, Black Box is a book by Israeli writer Amos Oz.

Black box: other meanings

• In phone phreaking, the black box was a device built by phone phreaks during the 1960s and 1970s to defeat toll charges.
• A black box theater is a simple, somewhat unadorned performance space, usually a large square room with black walls and a flat floor.
• Blackbox is a window manager that works on X Window System platforms.