So as noted here before, and it’s a pretty big distinction for how films are crewed and scheduled at The Film School and in the real world, jobs are classified as Above-the-Line (ATL) and Below-The-Line (BTL).
It’s not too hard to remember the difference. Writers, Directors, Producers, and Actors are ATL (as well as their assistants). Everyone else is BTL (Director of Photography, Gaffer, Grip, Editor, etc.). Of course in The Film School things are a bit different.
ATL in The Film School is Writer/Director, Producer, Director of Photography, 1st Assistant Director, and Art Director. The reason for the adjustment is these jobs require the most preparation so when the shows are scheduled no one will have to do two ATL jobs in one weekend.
So why the distinction? ATL salaries are generally negotiable (actress getting $20 million, a screenplay selling for six-figures…), while BTL jobs generally have a fixed rate. The names came about from the early studio days, when actors, directors, writers, and producers were listed first on the budget top-sheet, and then a big black line separated them from all the other costs.