Reliefs otherwise known as relievo which comes from the term relevo which is Latin for "to raise." There are several different kinds of reliefs but they all refer to a type of sculpture when the sculpture is raised. Three primary types are
High Raise:
Where more than half the sculpture is raised from the base.

Low Relief: Sometimes used on coins and has a shallow overall dept. It is common in ancient Egyptian artwork.
Recessed Relief: Is when it its sunken into the base. Often found in Egyptian art.