- A component, device, or unit with an input and an output, which can be inserted into a system without the need to know its internal structure. It is simply used based on its input and output characteristics. Also called closed box (1).
- In computers, a hardware or software unit whose internal structure is unknown, but whose function is known. Also called closed box (2).
- A sturdy self-contained electronic device which records key information concerning an aircraft, such as flight data.
Information & Library Science
- noun a device used for converting protocols from one computer system to another, such as for converting data from a micro to a phototypesetter