Alto-relievo is a term used in the art world to describe a sculpture or carving that is raised in prominent relief from a flat surface. There are several synonyms for this term that can be used to describe this kind of art style. For example, high relief is a commonly used term that refers to sculptures or carvings that have a depth that is greater than half of the width. Another synonym is bas-relief, which describes sculptures or carvings that are raised less prominently than alto-relievo, with a depth of less than half the width. Low relief is another term used to describe sculptures or carvings that have a very slight depth and minimal projection from a flat surface.