The iPhone X is equipped with an edge-to-edge 5.8‑inch Super Retina Display, which means it has no physical Home button like previous models. This eliminates the need for Touch ID and introduces a new way to unlock your device. The iPhone X uses Apple's all-new TrueDepth Camera and Face ID to unlock.
Face ID replaces Touch ID as Apple's new way to secure, unlock, authenticate, and pay. The new TrueDepth Camera "projects and analyzes more than 30,000 invisible dots to create a precise depth map of your face," according to Apple. It is also so secure that it can be used with Apple Pay, and it is able to resist spoofing and masks so other people can't break into your phone. The built-in A11 Bionic chip is designed to remember you even when your appearance changes or when you are wearing glasses, hats or makeup.
Apple promises that Face ID is so secure that it will only unlock when you look toward the device with your eyes open.