TRS
See Tip Ring Sleeve at Wikipedia
Excerpt:
1. Sleeve: usually ground
2. Ring: Right-hand channel for stereo signals, negative phase for balanced mono signals, power supply for power-requiring mono signal sources
3. Tip: Left-hand channel for stereo signals, positive phase for balanced mono signals, signal line for unbalanced mono signals
4. Insulating rings
2. Ring: Right-hand channel for stereo signals, negative phase for balanced mono signals, power supply for power-requiring mono signal sources
3. Tip: Left-hand channel for stereo signals, positive phase for balanced mono signals, signal line for unbalanced mono signals
4. Insulating rings
| Unbalanced | Balanced | Stereo | |
|---|---|---|---|
| Tip | Signal | Positive/"Hot" | Left channel |
| Ring | Not present | Negative/"Cold" | Right channel |
| Sleeve | Ground/Return | Ground | Ground |