Control Centre will be quite different in iOS 11. In addition to all the controls in iOS 10 it will also have screen recording and a new app switcher. The app switcher can show 4 to 6 app thumbnails at a time. That means you can find your apps faster and with less scrolling. Tap and hold on feature icons to open their controls.
You also have the ability to customize part of the Control Centre by choosing a bunch of app and feature shortcuts to show. Some of these shortcuts are Apple TV Remote, Magnifier and Text Size.
To close apps you tap and hold the thumbnails until they start to wiggle. Then you tap the x.
Feel free to ask if you have questions about the new Control Centre. Remember that functionality can change before iOS 11 is released.