Duplex

1. Indicates a communications channel capable of carrying signals in both directions.
2. In asynchronous communication, a channel that can simultaneously send and receive data.
3. Duplex printing is a print job that prints on both sides of the paper; so when bound, the corresponding pages face each other in a book/magazine.
4. Duplex system is a preventive measure operated by two computers; one computer doing the processing and the other standing by waiting for the execution.

Also see: Echoplex, Full duplex, Half-duplex