The Scene

"The structural unity of the parts is such that, if any one of them is displaced or removed, the whole will be disjointed and disturbed. For a thing whose presence or absence makes no visible difference is not an organic part of the whole." – Aristotle 

A SCENE is a unit of action that takes place in one location at one time. And in a screenplay, a scene must push the story forward and/or reveal character. If it does neither, kill it!