switch statements allow your code to take different paths, as if you're at a crossroad and decide which way to go depending on a condition. Loops, on the other hand, allow your code to take a few roundabouts before merging back into the main road. How many repetitions? That depends on the result of evaluating a condition before (or after) each iteration.
Let's say you are (your program execution is) traveling from A to B. At some point, you reach a place where you evaluate a condition, C. The result of evaluating C tells you if you should go into a loop, L. You make one iteration and arrive at C again. Then, you evaluate the condition once again to see if another iteration is needed. Eventually, you move on your way to B. ...