SHAPE

Shape: it is the external appearance of an object or element in a image.
Natural shapes: they are created only by the nature there isn't any help of human.
Artificial shapes: they are shapes that there is created by humans or mechanical procedares.
Organic shapes: they are shapes that have irregular profile or silhouette as well as their inner surface.
Geometric shapes: they are shapes whose parts follow a mathematic order, laws or pattern.
Flat shapes: they have two dimensions such a paper sheet.