For iOS 11, Apple has completely overhauled the Control Center. The Control Center is that tray that pops up when you swipe up from the bottom of the display on your iPhone or iPad (it will come from the top right side of the screen on the iPhone X). Traditionally, it's offered quick access to things like your phone's Wi-Fi and Bluetooth controls, Aeroplane Mode, the torch and music controls. It's essentially a place for shortcuts to different phone controls and with iOS 11 it's gotten a lot smarter.