An animator is one who is involved in the process of animation. How this person actually creates animation depends on the field in which he or she works.
Some fields in which an animator may work:
Among the specialized categorizations of animators are character animators (artists who specialize in character movement, dialogue, acting, etc.) and special effects animators (who animate anything that is not a character; most commonly vehicles, machinery, and natural phenomena such as rain, snow, and water).
Other artists who contribute to animated cartoons, but who are not animators, are layout artists (who design the backgrounds, lighting, and camera angles), storyboard artists (who draw panels of the action from the script), and background artists (who paint the "scenery").