PRINCIPAL ACTOR: The actor who has the main role, or lead actor.
CONTRACT ACTOR: An actor who is hired for a specific period of time only.
SUPPORTING ACTOR: An actor who is not the lead actor.
DAY PLAYER: An actor hired to play a supporting, speaking role. They are hired on a daily basis without a long-term contract.
UNDER FIVE: Any actor who has fewer than five speaking lines.
EXTRA: Minor actor used in crowd scenes (the background).