Heh, yeah, very different. I meant from a narrative standpoint. It's just one such term for 'the thing that gets your story moving', but from a writer's perspective. Essentially, you need to have your 'hook' in those first ten pages of a script. I've been told that's how a lot of people in the industry view it...which can be a problem. Audiences might be the same, unless they're used to a particular writer or director's style.
In classical terms, it is whatever sparks the hero into action. So, for Star Wars, it would be Luke getting Leia's message. Though I don't think that actually happens until after ten minutes in. Some films might begin in medias res, to get the action right up front. Hell, Indiana Jones films sort of begin with the end of 'another Indiana Jones film'.