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.

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