Metro is a new design language created for the Windows Phone 7 interface. Now, Metro concepts has propagated throughout a number of its products over the years. Zune, Media Center, Windows Phone, and Windows 8 all contain the principles, with Live Tiles marking an instant visual connection to a simplified interface. A great move for Microsoft towards simplicitic design. With the overwhelming flow of information, it's inevitable for us to move back to the basics by removing all the unnecessities and clutteredness of UI.