Asodium atom has one outer electron and a carbon atom has four outer electrons how might this difference be related to the types of compounds formed by atoms of these two electrons

The compound formed by carbon would be very stable and need more energy to break than the sodium compound

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