A film director is a person who directs the making of a film. A film director controls a film's artistic and dramatic aspects and visualizes the screenplay (or script) while guiding the technical crew and actors in the fulfillment of that vision. The director has a key role in choosing the cast members, production design, and the creative aspects of film-making. Under European Union law, the director is viewed as the author of the film.
The film director gives direction to the cast and crew and creates an overall vision through which a film eventually becomes realized, or noticed. Directors need to be able to mediate differences in creative visions and stay within the budget.
The Director must enforce their vision into the final version of the film by helping with any aspects regarding creative liberties. This can include, casting, editing, cinematography, set design, and even deciding who is part of the crew.
As a Director, many creative skills are required which directly translates into high pay. With that being said, it also wildly varies depending on the amount of experience in the job. As a newbie you can expect anywhere from $30k-$60k while people who have been a director for ~15-20 years can expect anywhere around the $150k-$200k mark.
Technically, you don't need any college credentials to become a director but to make it to big professional productions it is most likely needed to get into an entry level job. Most get a Bachelor's degree in film school and become a screenplay writer or cinematographer before becoming a director to get experience under their belt.