The upcoming iPhone X will use Face ID, technology that unlocks your iPhone X by using infrared and visible light scans to uniquely identify your face.
1,) It replaces the iPhone home button fingerprint sensor, Apple is considering two step verification using FaceID and the passcode.
2.) It will be used for authentication like Apple Pay too.
3.) It does not work when your eyes are closed or you are looking away
4.) If you squeeze the buttons on the right and left sides of the phone, it will lock the phone and force the use of the passcode
5.) After not recognizing the face scanned 5 times the phone will lock out FaceID attempts