End credits are the most complete public description of how a film was made, and they are written in a professional shorthand that assumes you already know the trade. A few minutes spent on the vocabulary turns an unreadable scroll into a fairly precise account of who did what.
The producing credits
The producing titles look interchangeable and are not. A producer is normally the person who carried the film from development through delivery. An executive producer credit most often marks someone who supplied or arranged financing, or who holds a senior position at a company involved; it can also be honorary. A line producer runs the production day to day and owns the budget. A co-producer sits below producer, often heading a department or a unit.
These distinctions are governed partly by guild rules and partly by negotiation, so the same title can mean different things on different films. Where the credit order looks strange, negotiation is usually the explanation.
The camera and lighting departments
The director of photography, also credited as cinematographer, is responsible for the image: lighting, lens choice, camera movement, and how the film is exposed. The camera operator physically operates the camera; on many films the DP does not. Focus puller — formally first assistant camera — sets focus during the take, which on a moving shot is a considerable skill.
Lighting is run by the gaffer, the chief lighting technician, whose deputy is the best boy electric. Grips handle everything the camera sits on or moves along and all rigging that shapes light without producing it; the key grip leads them, with a best boy grip as second. The terms are old and opaque, but the division is clean: electricians make light, grips control it and move the camera.
Sound
Production sound is recorded on set by the production sound mixer, with a boom operator placing the microphones. Almost everything else you hear is built later. A supervising sound editor runs the post-production sound crew. Foley artists perform footsteps, cloth movement and prop handling in sync with the picture. ADR is dialogue re-recorded by the actors after the fact, either to replace unusable production sound or to add lines. The re-recording mixer balances all of it into the final mix.
Second unit and the rest
A second unit shoots material that does not require the principal cast on camera — inserts, establishing shots, vehicle work, some action. It has its own director and often its own DP. On large productions the second unit may shoot a substantial share of the finished film.
Visual effects credits divide broadly between the supervisor, who plans and oversees the work, and the vendors who execute it. Where several vendors appear, they have usually split the film by sequence.
Why the order matters
Credit order is contractual. Position, size, whether a name appears on a card alone or shared, and whether it appears before or after the title are all negotiated and enforceable. When a credit sequence looks oddly arranged, it is generally recording an agreement rather than an oversight — which is why credits are a reasonable primary source for who was involved, and a poor one for who mattered most.