3-pole 6.3 mm. stereo Jack cables (Jack plug with 2 rings + tip), used for several purposes, it can either be used for balanced mono sound connections, e.g. in connection with adapters for XLR connectors. But of course also for unbalanced analog stereo sound by e.g. professional or high-end headphones or older audio equipment.

2-pole 6.35 mm. Jack plug cables (Jack plug with 1 ring + tip) are most often used for professional equipment, e.g. electronic musical instruments (drums, guitar, etc.), jack patch cables for mixers, stage boxes, etc.