Movie making is a complicated business, but the workload is generally split into three sections: pre-production, principal shooting and post production. Pre-production involves matters such as scriptwriting, financial backing, hiring of cast and crew, and scouting for locations. Once all of these details have been worked out, principal shooting can begin. This is the actual filming of individual scenes, without any special effects or musical background. Because time is money, principal shooting days are often long and hectic for actors and crew alike.

All of this planning and filming leads up to the most vital aspect of film making -- post production work. Post production turns individual scenes, called raw footage, into a finished motion picture. Editors splice all of the usable footage together into a coherent storyline according to the script. Composers add background music to create dramatic or comical effects. Special effects teams add computer-generated images and backgrounds to enhance the set or provide an as-yet-unseen character. All of this work can only be performed during post production.

Post production may also involve fixing mistakes not corrected during principal shooting. Quite often an actor's microphone will not pick up crucial bits of dialogue or another microphone may pick up extraneous noises. During post production, an actor may have to return to a soundbooth in order to re-record lost dialogue or improve the original delivery. This is called looping. Another function of post production is to add incidental sound effects not captured during the original scenes. A specialist called a foley artist will record such sounds as an actor's footsteps, a creaking door or gunshots.

Many directors and producers rely heavily on the ability of post production teams to create a marketable film. Since principal shooting can be a hectic time for both actors and directors, some footage may prove to be unusable during the post production editing process. A film's original ending may also be unpopular with test audiences. This could lead to reshoots with the principal actors before a final film is produced. Other responsibilities during post production may include publicity tours, promotional posters, contracts with distributors and the creation of auxiliary formats such as DVDs and soundtrack albums.