The Fullscreen API adds methods to present a specific Element (and its descendants) in fullscreen mode, and to exit fullscreen mode once it is no longer needed. This makes it possible to present desired content—such as an online game—using the user's entire screen, removing all browser user interface elements and other applications from the screen until fullscreen mode is shut off....Note: Navigating to another page, changing tabs, or switching...video is presented in a web page. Pressing the Enter key lets...