A shape is a graphical representation of the form of an object or its external boundary, outline or external surface. The cited Wikipedia article, which is where the term geometric shape leads, says it is distinct from other object properties such as color, texture or material type, and that in geometry shape excludes information about the position, size, orientation and chirality of the object. A figure is a representation including both shape and size, a plane shape is constrained to lie on a plane, in contrast to solid three-dimensional shapes, and a two-dimensional shape may lie on a more general curved surface. Objects recorded in the atlas as geometric objects are grouped under this concept.