3 Face ID and TrueDepth
Speaking of Face ID, Apple’s patented that, too. Interestingly, Apple filed for this patent in 2013, suggesting Face ID may have been in development for a few years before iPhone X. Face ID’s unique approach to facial recognition is very accurate and reliable, and may be faster than Touch ID in most practical uses.
Face ID is made possible by Apple’s TrueDepth camera system which also allows for facial mapping. TrueDepth helps make Portrait Mode and Animoji possible, and is available to third-party developers as well.