Full duplex is a term used to describe communication channels that transmit data in both directions simultaneously. There are several synonyms for full duplex, including two-way communication, dual-duplex, and bi-directional. Full duplex is also known as "full-duplex mode" or "full-duplex operation," which refers to the ability of a communication device to send and receive data simultaneously. Other related terms include half duplex, which only allows transmission in one direction at a time, and simplex, which only allows transmission in one direction. Full duplex is a useful feature in various communication systems, including telephony, radio communication, and computer networking.