A director generally has control of the production of a shoot. For TV and films, directors are often the top-level creative vision or author of the project, whereas on commercials, directors usually work with an ad agency to develop the final creative. These ad projects often have a director of photography or cinematographer credit instead of a director credit. A directors job is to realize the artistic and technical parts of a production, and they work closely with production team and talent to achieve the finished product.
Source: PayScale Canada