Why is photosynthesis important for ecosystems everywhere

Photosynthesis is necessary for providing energy for an ecosystem. Plants produce energy by the sun. This allows animals to eat the plants, getting its energy. Then predators can eat those animals. When all of these organisms die, then decomposers eat the decaying matter.

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