Sexual reproduction contributes to genetic diversity by allowing

Sexual Reproduction contributes to genetic diversity by allowing the chromosomes of both parents to mix together into the offspring making them a combination of both of the parents.

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