The first definition emphasizes the power of line to divide or connect different areas in a composition. The inherent dynamism of line is beautifully expressed in the second definition. Shape is created by a closed line, or by a solid color or value. Geometric shapes dominate the constructed environment of bridges, buildings and machines, and frequently occur in the patterns developed by pre-technological societies. Organic shapes are generally found in the natural world.
Texture refers to the visual or tactile surface of a shape or field.
Texture can add visual weight and volume to shapes, creating the illusion of three-dimensionality. It can also help distinguish shapes within a monochromatic composition. Color is the most complex and emotionally charged of the formal elements.