A telecommunications term referring to bidirectional communication. In full-duplex communication, both stations send and receive at the same time, and usually two communication channels are required. However, you can also achieve full-duplex communication using a multiplexing technique whereby signals traveling in different directions are placed into different time slots.
The disadvantage of this technique is that it cuts the overall possible transmission speed by half.
In half-duplex communication, only one station can transmit at any given time while the other station receives the transmission. The opposite of duplex communication is simplex.