The UITabBarItem class implements an item on a tab bar, instances of the UITabBar class. Tab bar items are used to configure the tab bar.
Tab bar items gives the ability to switch between different subtasks, views, or modes. A tab bar operates strictly in radio mode, where one item is selected at a time—tapping a tab bar item toggles the view above the tab bar. There is a way to specify a badge value on the tab bar item for adding additional visual information—for example, the Phone application uses a badge on the item to show the number of new messages. This class also provides a number of system defaults for creating items.