Android Action Bar

The Action Bar is a widget for activities that replaces the traditional title bar at the top of the screen. By default, the Action Bar includes the application logo on the left side, followed by the activity title, and any available items from the Options Menu on the right side. The Action Bar offers several useful features, including the ability to:

• Display items from the Options Menu directly in the Action Bar, as "action items"—providing instant access to key user actions.
  Menu items that do not appear as action items are placed in the overflow menu, revealed by a drop-down list in the Action Bar.
• Provide tabs for navigating between fragments.
• Provide a drop-down list for navigation.
• Provide interactive "action views" in place of action items (such as a search box).