Which activity is NOT part of the hydrosphere? A. rain falling from clouds
B. fish swimming in a pond
C. waves pounding a sandy shore
D. a stream tumbling over large rocks

D because most of the hydrosphere activities in include water

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