iOS Tip 182: The New Control Center

 

 In iOS 11 the Control Center has been reduced from the two or three pages in iOS 10 to
 a single page in iOS 11.

AND you can now customize Control Center to a certain extent in Settings >
 Control Center > Customize Controls. Most notably, you can add a
 variety of Apple-provided controls.
 
Although you can remove a few default controls, others are fixed:
 the networking platter, the media platter, Orientation Lock, Do Not
 Disturb, Screen Mirroring, Brightness, and Volume.