Reference

In general, a reference is something that refers to or designates something else, or acts as a connection or a link between two things. The objects it links may be concrete, such as books or locations, or abstract, such as data, thought, or memories. The object which is named by a reference, or to which the reference points, is the referent.In Art, a reference is an item from which a work is based. This may include an existing artwork, a reproduced or directly observed object, or the artist's memory.