The analog socket used to plug in a headset, earphones or headphones. The 2.5 and 3.5mm jacks have been used on cellphones and smartphones, while stereo and home theater equipment generally have a 6.3mm socket. In time, the common headphone jack on smartphones is expected to become history, replaced by wireless (Bluetooth). In 2016, Apple eliminated the headphone jack on the iPhone 7, requiring wired headphones to plug into the Lightning socket. See mini-phone connector
, phone connector
and Lightning connector
The 2.5 and 3.5mm jacks are used with mobile devices, while the 6.3mm connectors (bottom) are typically found on non-portable equipment.