Which type o go economic system do you think has been the most effective in promoting economic growth

Located throughout the body, veins return deoxygenated blood to the heart. Veins have valves to prevent backflow of blood and larger lumens (internal spaces) than arteries. The vein lumen has a smooth endothelium, or inner lining. The endothelium is part of the tunica intima, the innermost layer of the vein wall

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