This is one of the largest and most diverse of all the visual fields. Often called graphic design, it is now frequently referred to as communication design or visual communications, to more fully suggest the central role of communication in this field of work. Graphic design can cover virtually anything — including ads, magazines, signage, Web site, packages, or corporate identity systems — that involves combining words and images to communicate something to others. A strong sense of composition and color are essential, but so is experience in communication theory, sociology, and problem-solving. Some professionals in this field work on their own in a free-lance mode, although many work with others in offices (large or small) for corporate clients. (See also computer graphics.)