Shape is defined as a two-dimensional area or mass delimited by lines or color/texture contrasts. There are geometric shapes with mathematical order and organic shapes with irregular profiles. Shapes can be open without a fully enclosed line or closed with a well-defined outline. Positive shapes are the main figures, while negative shapes are the empty spaces around them. Key parts of a shape include the outline/contour enclosing it, the silhouette if filled with solid color, and the infill lines/colors/textures within. Shapes can be used to suggest depth and distance through varying size, overlapping, and using warm/cool colors.