An illustrator is an artist who specializes in enhancing writing or elucidating concepts by providing a visual representation that corresponds to the content of the associated text or idea. The illustration may be intended to clarify complicated concepts or objects that are difficult to describe textually, which is the reason illustrations are often found in children's books.

Illustration is the art of making images that work with something and add to it without needing direct attention and without distracting from what they illustrate. The other thing is the focus of the attention, and the illustration's role is to add personality and character without competing with that other thing.

Illustrations have been used in advertisements, architectural rendering, greeting cards, posters, books, graphic novels, storyboards, business, technical communications, magazines, shirts, video games, tutorials, and newspapers. A cartoon illustration can add humor to stories or essays.