Spec script (short for speculation script) is a script written with the typical screenwriting format, structure and story characterisation, with the intent to have that script optioned or purchased. A spec script serves as a window to the story of said script, and should have enough detail to to draw the reader into the story. Unlike the shooting script, the spec script doesn’t need and camera angles and any technicalities such as the lighting of the scene and so on.
Shooting scripts. This is written under the guidance and direction of the director of film, after the spec script has been optioned/purchased. In this version of the script is where things like camera angles and lighting are worked into the body of the script. Shooting scripts also often times story the process of storyboarding.
Official-Workbook 