In Windows 8, the various controls for open applications are hidden. The purpose of this action is to give the user a more streamlined experience, especially on small screens, as Windows 8 runs on mobile devices in addition to desktop and laptop computers. When you swipe up, down, from either edge or right-click within an app, the App commands (App bar) appears at the bottom of the screen (shown below).
This bar is similar to the File menu users found in previous versions of Windows; it contains advanced user options for each app. These options change depending on which app is currently in use.