Articulate Storyline 360: Definitions of "When" options in the Triggers?

Can anyone please point me in the direction of a 'cheat sheet' for how each of the "When" options in the Triggers work?
I'm struggling with a project I'm working on because I don't know how some of the triggers actually work. "When the user drags", for example, isn't doing what I thought it would, so I need to identify which will do what I'm trying to accomplish.

Thanks.