The term 'SCRIPT UNIT' is composed of three parts: SCENE (5 letters), LINE (4 letters), and LETTER (6 letters). A script unit is a unit of measurement used in the film and television industry to measure the length of a script. It is calculated by counting the number of scenes, lines of dialogue, and letters in a script. A SCENE is a part of a script that takes place in one location and usually involves one or more characters. A LINE is a single LINE of dialogue spoken by a character. A LETTER is a single LETTER of the alphabet.