"Charms" is a great new feature in Windows 8 as part of its interface and design. Charms allows the user to take advantage of relevant options which stay hidden until needed. I consider this new feature similar to the right-click for full-screen applications with the difference that traditional right-click context menus don't fit well when an app runs in full-screen mode.
The most common are the system charms. Docked in bars appearing on all sides of the screen, the system charms are useful for almost any application you open and they appear on the classic desktop too. See the image below.
If you own a touch-device, slide your finger inward from the right side of your screen to open up the charms menu. Desktop and laptop owners must point the cursor top-right side of the screen and move it down slowly. The charms menu will appear. A more simple way to open up the menu is to use the key combination Windows key + C on your keyboard.
There are several options that come along with the charms bar. It enables you to open the Start screen, search your computer or the application you're currently using and also allows you to shut down the computer.
On the Start screen, at the bottom and the top, there are other additional charms in application bars. These are context menus which are specific for each particular application. These options allow you to perform specific tasks like accessing tile settings of a selected tile or open a new tab in Internet Explorer. For more details see the image below.
The 3rd type of charms enables you to switch between apps. It offers a thumbnail view of your desktop and the Metro-style apps. Located on the left side of the screen, you can open up this charm by sliding your finger inward from left to right or point the mouse in the top-left corner of the screen then slowly mode it down. However, the easiest method to open the charm is to use the key combination Windows key + Tab.
For more in-depth information on Windows 8 Charms bar, watch this video: