An illustration is a decoration, interpretation or visual explanation of a text, concept or process, designed for integration in print and digital published media, such as posters, flyers, magazines, books, teaching materials, animations, video games and films. An illustration is typically created by an illustrator. Digital illustrations are often used to make websites and apps more user-friendly, such as the use of emojis to accompany digital type. Illustration also means providing an example; either in writing or in picture form.

In the art world, illustration has at times been considered of less importance than graphic design and fine art.

Today, however, due in part to the growth of graphic novel and video game industries, as well as increased use of illustration in magazines and other publications, illustration is now becoming a valued art form, capable of engaging a global market.