Face ID

Face ID refers to Apple's facial recognition technology in devices equipped with TrueDepth front-facing cameras and DOT projector.

History
Face ID was first introduced in the iPhone X in November 2017. It is also supported in the 3rd generation iPad Pro and later, as well as recent iPhone models without a home button.

In 2022, Apple began beta testing iOS 15.4, which allows for Face ID while wearing a mask by focusing on recognition of facial features around the eyes. However, this option is somewhat less secure than full facial recognition.

Trivia
The TrueDepth sensor on the iPhone X and above is also used to animate Memoji.