Click each step to see the action, click the picture or use the arrow keys
Home Key: Returns to the home screen. Tapping and holding launches Google Now
Back Key: Returns to the previous screen.
Menu Key: Opens the menu for the current screen. Tapping and holding opens a list of recently used apps
Application Launcher: Opens a list of installed apps
Power/Lock Key: Locks the phone. Pressing and holding launches the home screen options menu
Volume Keys: Adjusts the phone's volume