What does bump mapping mean?

bump mapping meaning in Urban Dictionary

Bump mapping is some sort of surface. The essential difference between bump mapping and regular surface mapping is the fact that reflections and lights on a bump mapped 3D design varies from a regular texture.

bump mapping meaning in Computer Science Dictionary

Video accelerator technique that gives a surface the appearance of surface. Like, bump mapping could cause wall space to look bumpy or rough, without bump mapping it could just look regular and simple.