The status bar displays the clock, battery icon, notification icons, etc. Most of the time it is at the top of the screen. This is provided by the system; the application does not directly manipulate the contents of this panel.
The action bar (sometimes called the application bar), if it exists for the action, will be located at the top of the activity content area, usually directly below the status bar. Actions control the presence of the action bar and, if so, what it looks and works.
Navigation or system panels are HOME, BACK, etc. buttons. This is usually located on the opposite side of the screen from the status bar, and therefore is usually located at the bottom of the screen. This is provided by the system; the application does not directly manipulate the contents of this panel.
