Art
Art is a diverse range of human activities in creating visual, auditory or performing artifacts (artworks), expressing the author's imaginative or technical skill, intended to be appreciated for their beauty or emotional power. In their most general form these activities include the production of works of art, the criticism of art, the study of the history of art, and the aesthetic dissemination of art.
Concept Art
Concept art is a form of illustration used to convey an idea for use in films, video games, animation, comic books, or other media before it is put into the final product. Concept art usually refers to world-building artwork used to inspire the development of media products, and is not the same as visual development art or concept design, though all three are often confused.
Illustration
An illustration is a decoration, interpretation or visual explanation of a text, concept or process, designed for integration in published media, such as posters, flyers, magazines, books, teaching materials, animations, video games and films.
Art
There is no pulse so sure of the state of a nation as its characteristic art product which has nothing to do with its material life.
Gertrude Stein. Paris France. New York: Liveright, 1970. (p. 12).
Art
Scientific pictures are often not just about science. They may... have an undeniable aesthetic quality. They may even have been primarily works of art that possess a scientific message.
John D. Barrow, Cosmic Imagery: Key Images in the History of Science (2008)
Illustration
Here is the amazing thing about Easter; the Resurrection Sunday for Christians is this, that Christ in the dying moments on the cross gives us the greatest illustration of forgiveness possible.
T. D. Jakes in: Lessons On Forgiveness From T.D. Jakes, NPR Organization, 5 April 2012.