Whats the difference between an Action and a Movement?

Ok, I use the Animation Editor and I see action and movement, what's the difference? I have a jump and fall animation, but when my player is supposed to be Idle, he'll just be playing the fall animation, so but in that place where you pick if it's idle, movement, action, and (something else) whats the difference? I don't want my fall to over-lap my idle. how do I fix this?

Its all about priority. Action has the most priority so therefore it will play over any animation. Movement has lower priority so therefore it won't overlap action, but it will overlap anything under it.