A screenplay contains five mandatory elements: scene headings, action lines, character names, dialogue, and transitions.
Scene headings — also called sluglines — define whether a scene is interior or exterior, identify the location, and state the time of day. INT. MUMBAI APARTMENT — NIGHT is a standard slugline. Action lines describe what the camera sees and are always written in present tense. Character names appear centred above each dialogue block. Dialogue is the spoken text and is mandatory for revealing character and advancing plot. Transitions such as CUT TO: or FADE OUT. indicate scene changes; modern screenplays use them sparingly.