In jQuery Mobile, there are two standard types of toolbars: Headers and Footers.
It's very common to have a horizontal navigation or tab bar inside the header an/or footer; jQuery Mobile includes a nav bar widget that turns an unordered list of links into a horizontal button bar, which works well in these instances.
At any time, tapping the screen will toggle the visibility of the fixed toolbars: tapping the page when the toolbars aren't visible brings them into view, tapping again hides them until you tap again. This gives users the option to hide the toolbars until needed to maximize screen real estate.
To set this behavior on a header or footer, add the
data-position="fixed" attribute to the toolbar container.
A "fullscreen" position mode works just like the fixed mode except that the toolbars aren't shown at the top and bottom of the page and only appear when the page is clicked. This is useful for immersive apps like photo or video viewers where you want the content to full when whole screen and toolbars can be summoned to appear by tapping the screen. Keep in mind that the toolbars in this mode will sit over page content so this is best used for specific situations.