
Apple
Face ID replaces Touch ID, which scans your fingerprint to unlock the iPhone. Because the new iPhone X doesn't have a physical home button or a Touch ID fingerprint sensor, Face ID will be the only way to securely lock and unlock the iPhone X.
Apple says that Face ID will be able to handle and recognize any changes to your face, like beards, different haircuts, and putting on or taking off glasses and hats. And the technology will recognize your face in the day and night time.
During the event, Apple said there was a slim 1 in a million chance that someone else looks enough like you to unlock your iPhone X using Face ID.
Face ID will work with third-party apps that support Touch ID, and it'll also register your face for Apple's new animated emojis, or "animojis."

Apple