There are many moving parts to making a film. The most important role is that of the person that is responsible for ensuring all those parts are choreographed and work in unison to create a moving and dramatic story; the director.
Usually either employed by a Producer or the movie studio, the director of the movie is the one whose creative vision is conveyed in the film.
The director chooses or is assigned the screenplay, and determines the best way to dramatically tell the story that is written on paper. Together with the cinematographer, the director must also create the visual style and tone of the film as different stories call for a different aesthetic.
The director also oversees other creative aspects of the film such as costume, set design and music. The director can also be very much involved in the casting of a film, having had their own ideas of what certain characters from the screenplay would look, feel and act like. It’s through the director’s inspiration and creative vision that he conveys to the various hundreds of people involved in the making of a film, who then utilize they own creativity to match the director’s.
There are many different directing styles that can be as involved, or hands off, as the respective person wants. A director can either have complete and total control of a movie, and responsible for overseeing every element of the film-making process; or they can be completely disconnected and only act as an intermediary between the different departments assisting in the completion of the film. A director can also be the writer, producer, and in very rare instances the star of a movie as well.
A director is to a movie, what an author is to a novel.