Plate

A Plate is a type of LEGO piece. It is a brick, except flat rather than tall. Buildings are often built on a special kind of plate called a Baseplate, which is usually as wide or long as an average keyboard, depending on the model's size. Road Plates are baseplates with road decals on top of them, most used in racers sets. Of course, you can also buy an Expansion or Bonus Pack. A plate is a third the height of a brick. Something similar to a plate is a tile-a plate with no (or only some of the) studs on top.