The Copyright Act of 1976 is an exclusive rights protection for authors of either published or unpublished works like art, literature, dramas, and music. Original content can only be protected in a stylistic manner. For example, the story of Romeo and Juliet has been retold for centuries, however the musical Westside Story is copyrighted for it's portrayal, musical numbers, script, and choreography. Copyrights are registered and kept within the Library of Congress.
Only the creator of the original content is considered to be an author, and can thus claim copyright, unless the author signs a written agreement passing the copyright authorship to another individual or if an individual acquired a work by inheritance. Although there are restrictions depending on state law, minors are eligible to claim copyright. The author can come from any nation and register for copyright within the U.S. The U.S. also has treaties with certain countries in which copyrights are protected in both countries.
A copyright will protect both published and unpublished works. Beyond works of art, music, literature, and theater, works of programming, architecture, software, and systems can also be copyrighted. The difference between a copyright and a trademark or a patent is that copyright protects works that were authored whereas patents protect works that were invented or discovered, and a trademark protects a specific image or symbol associated with a product to distinguish itself within the market.
The practice of sending a copy of your own work to yourself is sometimes called a “poor man’s copyright.” There is no provision in the copyright law regarding any such type of protection, and it is not a substitute for registration.