Copyright (United States)
Legal rights dictating the ownership and use of media. Copyright laws generally function by prohibiting unauthorized duplication or derivation of media, although they do not protect the specific concepts or facts contained within that media. However, both parodies and critical analysis are explicitly exempt from the prohibition against using copyrighted media without permission.
As an example, copyright laws prohibit the duplication character of Harry Potter, but this does not mean the use of a male wizard in other works is also prohibited, so long as there are significant differences between the two characters. However, a TV comedy sketch could use the name "Harry Potter" if it is unambiguously part of a parody, and a book about magic in popular culture could use an image from a Harry Potter film if it seems legitimately warranted.
The aim of copyright as written in the Constitution is to promote creativity and progress by protecting the rights of the artist/creator.