A TRS (Tip Ring Sleeve) connector is a audio plug or connector with three contacts for balanced or stereo audio signals. It is also known as a 1/4-inch phone plug because of its use in the telephone industry.
It smaller cousin is the 1/8 inch or mini audio plug commonly used in computer sound ports and other consumer audio equipment.
There are two black stripes on TRS plugs. One seperates the tip from the ring the second separates the ring from the sleeve.
A similar connector is the TS (Tip Sleeve) connector for unbalanced signals.