The document discusses the origins and design of the Metro interface used in Windows 8. It describes Metro as taking inspiration from Bauhaus design principles of minimalism and focusing on functionality. Metro aims to be fast, fluid, digital, and reduce designs to their essentials. The document outlines Metro's visual language including use of typography, color, motion and touch interaction. It provides details on Metro app anatomy, navigation patterns, and layout guidelines. Case studies demonstrate how specific apps apply Metro conventions.