How does the environment define the ecologic roles of organisms?

Biodiversity plays an important role inecological health as much as it does for human health. ... Ecosystem engineers aredefined as: "...organisms that directly or indirectly modulate the availability

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