Each virus has a basic structure to it. Which of the following is NOT one of those basic structures? A. Membrane envelope
B. Capsid (Protein coat)
C. Carbohydrate strands on the outside
D. Genetic material (DNA/RNA)

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