Which cell part helps to control the materials that enter and leave a cell? A. nucleus
B. cell wall
C. cytoplasm
D. cell membrane

It’s D. Cell membrane.

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