A work of art, artwork, art piece, or art object is an aesthetic item or artistic creation.The products of environmental design, depending on intention and execution, can be "works of art" and include: land art, site-specific art, architecture, gardens, landscape architecture, installation art, rock art, and megalithic monuments.Artist Michael Craig-Martin, creator of An Oak Tree, said of his work - "It's not a symbol. I have changed the physical substance of the glass of water into that of an oak tree. I didn't change its appearance. The actual oak tree is physically present, but in the form of a glass of water.Some art theorists and writers have long made a distinction between the physical qualities of an art object and its identity-status as an artwork. For example, a painting by Rembrandt has a physical existence as an "oil painting on canvas" that is separate from its identity as a masterpiece "work of art" or the artist's magnum opus. Many works of art are initially denied "museum quality" or artistic merit, and later become accepted and valued in museum and private collections. Works by the Impressionists and non-representational abstract artists are examples. Some, such as the "Readymades" of Marcel Duchamp including his infamous 'urinal "Fountain'", are later reproduced as "museum quality replicas".
There is an indefinite distinction, for current or historical aesthetic items: between "fine art" objects made by "artists"; and folk art, craft-work, or "applied art" objects made by "first, second, or third-world" designers, artisans and craftspeople. Contemporary and archeological indigenous art, industrial design items in limited or mass production, and places created by environmental designers and cultural landscapes, are some examples. The term has been consistently available for debate, reconsideration, and redefinition.