You see the home screen when you turn on and unlock your phone or touch .
You can add pages to your home screen. Swipe left to add a page.
Here are the parts of your home screen:
Status bar: Displays the time and icons that tell you about your phone's battery and network connections. Swipe down to get to your settings and handy toggle switches.
Widget: You can add widgets to your home screen for quick access to information or frequent tasks.
Shortcut: Opens an app or a web page. You can add shortcuts to apps you use frequently, instead of opening and scrolling through your list of all apps.
Favourites tray: Provides one-touch access to your most-used apps from any of the home screen pages. To open the list of all your apps, touch .
Navigation: takes you back one screen. returns you to the home screen from any app. lets you switch between recent apps.
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takes you back one screen. 
lets you switch between recent apps.