is a visually perceived area created either by an enclosing line or by color and value changes that define the outer edges in a two-dimensional format.

consist of predictable, precise edges that appear to have a machine-made quality.

consist of natural, curving, unpredictable, edges.

have distinct edges created by abrupt changes in color, value, pattern, or texture

shapes are created by gradual or indistinct changes in color, value, texture or pattern. It is difficult to determine where one shape ends and another begina.