The difference between high and low relief sculpture is in how much they protrude from their background.
Step-by-step explanation:
Both high and low relief sculpture are built into or from the rock that forms their background or the larger structure. They are usually found as murals and decorative motifs in buildings.
They are identified into high and low relief sculpture according to their protrusion from the wall or background they are built into.
A low relief sculpture will seem to be a part of the structure and will look only slightly out and engraved while a high relief one would seem to be on top of the background and not a part of it because of how outward it will protrude.