The divisions of the plug in phone, mini-phone and sub-mini connectors that represent the different conductors. Tip (T) and ring (R), along with the sleeve (S), are used in two-conductor (TS), three-conductor (TRS) and four-conductor (TRRS) variations. This terminology originated from the early days of telephones when operators manually plugged lines into a manual switchboard. Today, there are myriad audio applications that use two conductors (TS) for mono and three conductors (TRS) for stereo. See phone connector and mini-phone connector.
The term tip and ring originated in the cordboard plugs that establish the connection between the copper wire pairs. The tip of the plug connects to the electrically positive (+) wire, and the ring, or seat of the plug, to the electrically negative (