FAVOURITES TRAY
At the bottom of every Home Screen you’ll find the Favourites Tray - another quick way to get your apps.
To open an app, touch it. To drag an app in or out of the Favourite Tray or anywhere else on a Home Screen, touch & hold it, then move it with your finger where you want it.
BOTTOM NAVIGATION BUTTONS
At the bottom of the phone, no matter what you’re doing, you’ll always find the navigation bar with three buttons. On your phone, it looks like this:
BACK 
Opens the previous screen you were working in, even if it was in a different app. Once you back up to the Home Screen, you can’t go back any further
HOME 
Opens the central Home Screen. To open Google Now™, swipe up
OVERVIEW 
Opens a list of thumbnail images of screens you’ve worked with recently. To open one, touch it. To remove a screen form the list, swipe it left or right or touch on the X.
Some apps hide these buttons temporarily, or fade them to small dots in the same position. To bring them back, touch the dots, touch the screen in the middle, or swipe up from the bottom.
MENUS
Many screens in Apps and Settings include a 
Menu Icon at the top right of the screen. Touch it to explore additional options, including Help and Settings.