Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane.
Surface area is its analog on the two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat.
It is the two-dimensional analog of the length of a curve (a one-dimensional concept) or the volume of a solid (a three-dimensional concept).
The human cerebral cortex has been estimated to contain anywhere from ~50 to ~200 areas per hemisphere. However, attaining a consensus whole-cortex parcellation has been difficult because of practical and technical challenges 1)