To open an app, tap its icon on the home screen, or swipe up from the bottom of your home screen to open the app tray, then tap the app.
To leave an app and go to your home screen, just swipe up from the bottom of the screen.
You don't need to close apps. Android manages the memory and battery that apps use, so you don't need to worry about leaving apps open.
To close one app, drag up from the bottom of the screen, hold, then let go. In your recent apps, swipe up on the app.
To close all apps, drag up from the bottom of the screen, hold, then let go. In your recent apps, swipe right until you see the start of the list, then tap Clear all. (You can prevent certain apps from being cleared.)
Your phone includes a sidebar that you can swipe open from the edge of your screen to access your favorite apps and actions. You can choose how apps open from the sidebar:
(If you don't see the sidebar, turn it on in Settings > Gestures.)

To open an app, swipe in from the edge of your phone where you see a translucent bar to open a menu of apps, then tap one to open it in a floating, freeform window or full screen.
To open an app in another mode (freeform or full screen), drag it from the sidebar to the center of the screen.
To open an app in a split screen, drag it from the sidebar to the top or bottom of the screen.
To move the freeform app, touch & hold 
To resize the freeform app, drag a bottom corner diagonally:
Drag all the way down to open to full screen.

Drag all the way up for a floating, movable icon you can tap to reopen the app.

To close the app, tap 
To customize the sidebar, tap 
To switch between recently used apps, swipe left or right at the bottom of the screen.
To see your list of recent apps, drag up from the bottom of the screen, hold, then let go:
You can clear all apps from your list of recent apps. Or, you can prevent an app from being cleared from your recent apps when you tap Clear all to close all apps.
To remove all apps from the list:
To lock an app in the list:

To unlock the app so it's removed when you tap Clear all:

To search this help, tap 
If you don’t see what you’re looking for, check for app-specific help:

