Screenplay versus Shooting Script

What is the difference between the pre production script and the script ready for production?

(Gathered from various sources over the internet)

The pre-production script also called the screenplay is the actual blueprint around which a film is built. However screenplays usually differ a lot from the final product because many scenes get modified or cut off and others are added even before filming starts. Yet, screenplay is generally page-locked and scene-numbered meaning the same scene will always fall on the same page even if scenes are deleted or added. A screenplay contains the essentials for making the film and is usually clean of things like camera angles, actor’s marks and prop specifics.

Script ready for production otherwise known as the shooting script is the screenplay which has been updated for the filming. The shooting script may not stay the same as well as it keeps evolving as the production takes place. A shooting script often contains a lot of annotations and updates including directives to the production crew such as the camera angles, prop positions, details about the actor’s position, action and gestures.