The purposes of design fall roughly into five categories: descriptive (to document the visible world), narrative (to tell a story or send a message), emotive (to evoke a mood), utilitarian (to perform a practical function), and decorative (to creatively arrange design elements, such as color and shape). Keep in mind that most designs serve more than one of these purposes. In fact, overlap is almost inevitable. Usually, however, one design purpose is primary, and the success of any design can be judged by how well it achieves its purpose.