The terms are interchangeable today. Sitcom - Situation Comedy. Typically a thirty minute television stage comedy with few to no exterior filming or videotaping. Performed in an interior set. Spec Script - a TV or film script that is written on speculation that it can later be sold upon completion with no agreement or contract with a principal.
New screenwriters use the spec script as a business card to demonstrate writing ability.
Story Beats - the main points of twists and turns in the story. A film may have a dozen beats or more. Studio - a principal that hires production companies or produces their own films. Synopsis - a one page detail of the script's story beats. Treatment - a breakdown of scenes in short paragraph form.