Black box

A black box is a system where we have a well defined understanding of its inputs and output characteristics, but no idea what's going on inside.

There are several main senses:

• In electronics, a sealed piece of replaceable equipment - see Line replaceable unit.

• In aircraft, the flight data recorders and cockpit voice recorders, that record aircraft and pilot behavior in order to analyze accidents are called "black boxes" by the news media. (Even though they are actually bright orange in colour, they were black when originally introduced.)

• In philosophy and mathematics - see black box theory.

• Black Box is a game which simulates shooting lasers into a black box to deduce the locations of mirrors hidden inside. It has been sold as a board game, and there are also numerous computer implementations for many different platforms.

• Phone Phreaking, the Black Box was a particular kind of device built by phone phreaks during the 1960s and 1970s to defeat toll charges.

• 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.

Also See

• Black Box, the theatrical term.
• Blackbox - a window manager that works on X Window System platforms.