I'll run you through switches.

A switch is what it sounds like. A switch. Think of it like this.

You're in your room and there's an old guy sitting in the corner.

He says (if Switch:Light=off) "Turn on the light, honey."

So you walk over to the light switch, and you turn the switch on.

There's another page to the old man's event. This time the precondition is (if Switch:Light=on) and the old man says, "Good job." and you recieve 1 groping.

Basically you can have up to, I forget... 600 something switches and you are able to name each one and they are either turned off or on by an event.

Do you need more of an example?