A cast member is someone who performs in a Motion Picture . The actors who perform in the motion picture are the cast.
A cast member is someone who performs in a Theatrical Production . The actors who perform in a show are also referred to as the cast.
A cast member is any employee of The Walt Disney Company . For example, employees at a Disney Theme Park , Disney Store or even telephone operators at the Walt Disney Travel Company. The term was christened by Walt Disney when training the very first employees of Disneyland , comparing them to 'creating a show', like an actor in a motion picture.