An important concept in copyright law is that two different artists can create a works which are identical without infringing on each other’s copyright. This concept is known an independent creation. Independent creation is where two separate people both create the same work, or works that are substantially similar, on their own and independent of each other. In United States copyright law independent creation can be a valid defense to a claim of copyright infringement. Independent creation is a defense to copyright infringement because the exclusive rights associated with a copyright are limited to the artist’s creation. Copyright protects an artist’s expression of an idea, not the underlying idea. This means that an artist that paints a picture of a tree cannot claim copyright infringement if other artists paint the same tree.