when the controller or console is turned off, hold this button to turn on the console. if the console is already on and the controller is off, hold this button to turn on the controller. when the controller and console are already on,hold this button to turn off the console. when using the console, press this button once to go to the home screen, no matter where you are. when viewing two snapped apps, press this button twice quickly to toggle between those apps. when using the controller with a windows 10 device, this button opens the game bar when pressed during pc gameplay.exception: during game streaming through the xbox app for windows 10, pressing this button returns you to the home screen of the xbox app for windows 10