The lava released by a volcanic eruption separates two populations of a species of monkey. what does this represent?
a biological isolation
b geographical isolation
c temporal isolation
d anatomical isolation

B. geographical isolation

Explanation:

When during the course of evolution new and distinct species are formed due to several mechanisms the process is known as speciation.Geographical isolation is one of the many events that can lead to speciation.Due to geographical isolation, the members of the same species are geographically isolated from each other and thus, start occupying different niches. With time these members accumulate different changes in their gene and as there is no genetic material that gets exchanged between them they form distinct species such that even after they meet they are not able to interbreed.

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