Many people confuse the terms jack and plug when describing connectors. A plug is the less fixed connector. The jack is the more fixed connector, often being soldered to a PC board or panel mounted. If one connector is board mounted it is defined as the jack if its mating pair, which would then be called the plug, is mounted in a cable assembly. Usually the plug is the male connector or the one with pins. The jack is the female connector or socket. Because these terms are so often confused it can be a good idea for everyone involved to look at the mechanical drawing on the specification sheet to ensure that terms have been used correctly.