Flat design is a simple, graphic style common in user interface (UI), software and Web design. The flat style contrasts with skeuomorphism, a design approach that seeks to bring real-world effects to the items that are represented.
A skeuomorphic icon representing a phone function, for example, is typically an image that resembles a real-world phone, complete with shadows, highlights and some degree of detail. Its flat design counterpart, on the other hand, is typically a simple graphic image, recognizable and representative but without any attempt to mimic 3-D effects.
Proponents of skeuomorphism claim that it renders objects in a way that is more visually appealing and more readily recognizable. Flat design proponents argue that device users have grown more sophisticated and no longer require that degree of replication and that its simpler designs are more honest because they are clearly not faking a 3-D (three-dimensional) effect.