What is the relationship between the size of a predator population and the size of a prey population

Well..using logic here, if there was a large size of predators, that would mean a small size of prey population since there'd be a lot of hunters hunting for prey. If there was a small number of predators there'd be a large size of prey population since there's less to feed...

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