I’m confused about how voting works in Washington. We have both a caucus and a primary, and both websites seem to be saying that they’re the ones who decide who gets the nomination and the other is just a formality.

I’m just trying to figure out if I need to register and go to my caucus, or if it's just a formality in my state? Because if I don't need to spend my Saturday listening to people argue politics then I won't. But if it's going to make a difference I will do it.