App And Navigation Bars
Most apps, and even the Start screen, have additional options that don't fit on-screen or get handled by Charms. In desktop applications, these functions are usually found in the uppermost toolbar or buried within the menu bar. Since Microsoft's Windows 8 UI has none of the usual windowing mechanisms, these functions had to go elsewhere.
Right-clicking in the Windows 8 UI usually brings up one or two bars: the App bar from the bottom of the screen and/or the Navigation bar from the top of the screen. Both the App and the Navigation bars change to suit to the current app. Below are some examples of the options and controls found in these bars.
On the Start screen, the App bar brings up the All Apps button.
The Start screen has no Navigation bar. The Windows Store, on the other hand, has a Navigation bar, but no App bar.
The Bing Weather app has both an App and a Navigation bar. The App bar has controls for changing your home location, using a current location (via location services), switching between Celcius and Farenheit, and refreshing the forecast. Meanwhile, the Navigation bar has options to switch to another location, return to the home location, and see an overview of weather around the world.
In Internet Explorer 10, the App bar, oddly enough, contains navigation controls (back, forward, reload, and a location/search bar). The Navigation bar in Internet Explorer 10 hosts thumbnail shortcuts for each open tab.
Programs use the App and Navigation bars to hide extraneous options, like the menu bars we're accustomed to. Between them (and the Charms bar), we're actually surprised how much room there is for added functionality. And yet, controls are all large enough to easily tap with your finger.
Speaking of, now that we understand how to get around the Windows 8 UI with a mouse, let's look at multi-touch.