The Charms bar
You can get to the Charms bar no matter where you are in Windows 8: Press the Windows key + C on your keyboard, or swipe from the right edge of the screen toward the center on a touch-screen device. The Charms bar appears with five charms on a black background: Search, Share, Start, Devices and Settings.
The Start charm in the center of the bar acts as a toggle: Click it to go to the Start screen or, if you're already on the Start screen, to go to your previous location. We'll explore the other charms in upcoming slides.