Surface relief is the depressions (low relief) and elevations (high relief) in the surface of an object. Examples include the peaks, valleys, and plateaus of a planet, or dimples of a golf ball.
Although you could model surface relief into an object’s geometry, usually it is faster and easier to achieve the same look with textures used as bump maps (which create the illusion of relief) or displacement maps (which create true surface relief by changing the topology of the object).
