Desktop-based app tiles don't show notifications, and they have smaller graphics on them. Also, tiles for Desktop apps often appear on the right side of the screen, and they (and other tiles as well) may be off of its edge, so you'll have to scroll (or swipe, if you've got a touch-screen device) to see them.
Charms bar. If you move your mouse pointer to the upper-right or lower-right corner of the screen, the Charms bar appears as an overlay on the screen -- sometimes directly on top of tiles or other content. This bar gives you quick access to features such as search and system settings from anywhere in Windows 8. I'll provide a detailed look at the Charms bar later in the story.
Scroll bar. The Start screen has a horizontal orientation, so when you want to see more tiles on the screen, you'll have to scroll or swipe to see them. The scrollbar is not normally visible, but it makes its appearance when you move your mouse. You use it as you would any normal scroll bar, except you'll scroll to the right and left rather than up and down.
User account. This shows the name of the current account logged into Windows 8, along with the picture associated with the account. Click it to change the picture, lock your device, sign out or switch to another account.
Check out "Customize the Start screen" later in this article for details about how to change tile sizes, rearrange tiles on the screen and more.
Your old friend the Desktop
The Desktop is no longer front and center in Windows 8, having been delegated to second-class status by the Start screen. As befits a second fiddle, you don't boot directly into it when you log into Windows. Instead, you run it like any other app by clicking the Desktop tile on the Start screen.
When you get there, you'll find a familiar-looking Desktop minus what had been one of its key features in previous versions of Windows -- the Start button and its menu. And that means that you're going to have to get used to a new way of using the Desktop and put up with some kludgy ways of accessing apps and features that previously were directly in reach. (But don't fret -- as I'll show you later in the story, there are non-Microsoft-approved ways to reinstate the Start button and even to boot directly into the Desktop.)