A film crew is a group of people hired by a film company, employed during the "production" or "photography" phase, for the purpose of producing a film or motion picture. Crew are distinguished from cast, the actors who appear in front of the camera or provide voices for characters in the film. The crew interacts with but is also distinct from the production staff, consisting of producers, managers, company representatives, their assistants, and those whose primary responsibility falls in pre-production or post-production phases, such as writers and editors. Communication between production and crew generally passes through the director and his/her staff of assistants. Medium-to-large crews are generally divided into departments with well defined hierarchies and standards for interaction and cooperation between the departments. Other than acting, the crew handles everything in the photography phase: props and costumes, shooting, sound, electrics (i.e., lights), sets, and production special effects. Caterers (known in the film industry as "craft services") are usually not considered part of the crew.