(Note: If the term appears in ALL CAPS below, then it must be written in ALL CAPS in your script)
Montage: A series of images showing a theme, a contradiction, or the passage of time.
O.S. or O.C. Off-screen or Off-camera. This is the abbreviation sometimes seen next to the CHARACTER'S name before certain bits of dialog. It means the writer specifically wants the voice to come from somewhere unseen.
POV Point of View. The camera replaces the eyes (sometimes the ears) of a character, monster, machine, surveillance camera, etc. As a result, we get to see the world through the senses or sensory devices of an "other."