6.35 mm (¹⁄₄ in) plugs are common on home and professional component equipmen,that two-contact phone connector used for various signals includingelectric guitar,loudspeaker, microphoneand line-level audio. 

Q: What does TS mean? What is a TS connector used for?

A: TS is the abbreviation for “Tip, Sleeve” and refers to a specific type of 1/4″ connector that is set up for 2-conductor, unbalanced operation. One insulator ring separates the tip and sleeve. The tip is generally considered the “hot,” or the carrier of the signal, while the sleeve is where the ground or shield is connected. TS cables are best known as guitar or line-level instrument cables.

Q: What does TRS mean? What is a TRS connector used for?

A: TRS is the abbreviation for “Tip, Ring, Sleeve.” It looks like a standard 1/4″ plug but with an extra “ring” on its shaft. TRS cables have two conductors plus a ground (shield). TRS connectors are commonly used to connect balanced equipment or for running both left and right mono signals to stereo headphones.

Q: Why is a ¼” connector sometimes called a “phone plug”?

A: The original 1⁄4 in (6.35 mm) version dates from 1878, when it was used for manual telephone exchanges, making it possibly the oldest electrical connector standard still in use. It was used for years by telephone operators to patch telephone connections together.