TRS
Stands for "Tip-Ring-Sleeve."
TRS is an analog audio plug with three connection points (tip, ring, and sleeve). It comes in two standard sizes: 1/4-inch and 1/8-inch. An 1/8-inch (or 3.5 mm) TRS jack is often called a "headphone jack" since it is the standard audio connector used by headphones.
A TRS plug has two lines separating the tip, ring, and sleeve.
- Tip - Carries the left (L) channel of a stereo audio signal or the positive phase in a balanced mono connection
- Ring - Carries the right (R) channel of a stereo audio signal or the negative phase in balanced mono
- Sleeve - Functions as the ground or shield in both stereo and balanced connections
TRS vs XLR
Both TRS and XLR connections have three connection points and typically carry audio signals. However, TRS can transmit stereo audio (left and right channels) over a single cable, while XLR can only transmit a balanced mono audio signal.
XLR connectors have a rugged design and may include a clip to keep the jack in place. Therefore, XLR cables are typically used for live/stage audio and long cable runs. 1/4" TRS cables are typically used for direct connections to instruments like keyboards and guitars. 1/8" TRS audio output ports are most often found on small devices, such as laptops and smartphones.
NOTE: A mono TRS plug is called a TS or "tip-sleeve" jack. TS cables carry a mono audio signal, such as output from an electric guitar.