Flat design is a minimalistic design approach that emphasizes usability. It features clean, open space, crisp edges, bright colors and two-dimensional/flat illustrations.
Microsoft was one of the first to apply this design style to its interface. Instead of converting a real-life object, such as a calendar, into a tiny realistic illustration, advocates of flat design identify apps with simple, icon-like images. Rather than bringing aspects of real life to an interface, this illustrates a clear separation between technology and tactile objects.