Black Box

In science and engineering, a black box is a device, system or object which can be viewed solely in terms of its input, output and transfer characteristics without any knowledge of its internal workings, that is, its implementation is "opaque" (black). Almost anything might be referred to as a black box: a transistor, an algorithm, or the human mind.

The opposite of a black box is a system where the inner components or logic are available for inspection, which is sometimes known as a clear box, a glass box, or a white box.