Earth's surface features are continually changing... this is due to a) wearing away of the surface

b) building up of the surface

c) both wearing away and building up

Cartificial intelligence

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it