Answer: For context, a relief sculpture is done on a flat surface. It looks more like a carving. A relief might be easier to create is it can be mounted, shaped like a drawing, and perhaps less heavy. A drawback might be that it’s less three dimensional, or that it might be harder to make it more realistic.
So all you have to do is look around your house and see what texture you can see and what things feel rough. Or if it feels smooth, soft, hard, light or heavy then that is what you write.