Any Metro app you install can extend the search feature and add its own search results – for example, a music-playing application could add song, artist, and album results. From here, you can search your installed apps and files.
When you invoke it from the desktop or the Start screen, you’ll access the system-wide search functionality. The Search charm can be either context-sensitive or global. You’ll see five charms: Search, Share, Start, Devices, and Settings.
