Leaves are green because they contain what green substance?

Chlorophyll, it's a chemical that plants produce that give them their green color

Leaves are green because they contain chlorophyll 

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

Mechanical energy from wind nonrenewable resource