What is the difference between the control group and the experimental group in a experimental study

A control group is going to be something that you don’t “experiment on or change. It is grown or watched under normal conditions. This way you have a medium to say how things are “supposed” to go.

The experimental group is going to be where you “experiment” and change the normal conditions to see what outcome will occur ( under different conditions then normal )

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