A socket, receptacle or port. The term is widely used in the telephony and audio/video worlds; for example, the Registered Jack-11 (RJ-11) is the common telephone wall outlet. Microphones plug into phono jacks on amplifiers. In networking, "port" is the preferred term as in "the switch has 24 RJ-45 ports." However, people coming from the telephony world might say "the switch has 24 RJ-45 jacks." See
audio jack,
RJ-11,
RJ-45 and
plugs and sockets.