Producers are the overall decision makers, they oversee every stage of production, from script to screen. They are responsible for managing funds, getting scripts and writers and approving locations for filming.
The executive producer is somewhat similar to the producer however, these are often freelance and their involvement varies. Sometimes this role is given to a writer who had little to no involvement in the production. Executive producers are applied to TV drama rather than film.
Directors are hired by the producers or executive producers, and are given a script. It is not rare for the director to be the screenwriter as well. They are responsible for the creative process, working on set giving actors, lighting, wardrobe and make up crews directions. After filming directors lead the editing process, creating a 'directors cut', this is then given to producers and financers to review before the final cut.
Casting directors are hired by the production company to seek out actors based on their likeness to the character. They have meetings with the producers and directors to get a sense of the type of person they are trying to find. They keep in mind the availability of the actor, their fees, and how much excitement they'll bring to box office. They are responsible for scouting potential talent.
Marketing managers are responsible for publicizing the production. They identify the audience and, create posters, billboards, social media, newsletters, trailers, etc. to convince the audience this is a must see production. They keep in mind the budget for income forecasts, acquisition costs and contract terms. If a film is international they need to consider different campaigns to adapt different cultures and countries.
Publicists, on the other hand, get the critics talking. They have good relationships with critics and journalists therefore giving the movie media coverage. They create press packs and schedule interviews, sometimes even bringing journalists to set during shooting. They also inform the distributor and producer of PR developments. If there's controversy they deal with damage control. They need to be available 24/7.
