Another analogy to think of it is having two areas of lowered terrain with a civillian in one of the holes. Now, you can use triggers to move this civv back and forth from which hole he is in. Also, you can activate or prevent triggers by having this civv in a specific hole by simply using the "bring" condition.
Switches are the same; they are either Cleared or Set, and you can make actions to either Clear or Set a switch, as well as make them conditions in a trigger. They all start cleared.
I hope my little comparison helped
