Apple has incorporated biometric authentication into the iPhone since the 5s, when Touch ID was introduced. Last year, thanks to the TrueDepth camera that's able to map 3D surfaces, the iPhone X included a brand-new feature called Face ID. iPhone X owners who've set up FaceID can use the feature to unlock their devices, as well as pay for purchases in the iTunes store, Apple Books, the App Store, and to make payments with Apple Pay. Although this feature does add significant convenience to the iPhone experience, many Face ID users have complained that only one person can be registered per device, as opposed to the five different fingerprints that could be set up in Touch ID. It looks as though this issue may be solved with iOS 12, though, because the Beta version gives users the opportunity to register an Alternative Appearance upon setting up Face ID.
