Copyright begins when intellectual property is created and is put in a "fixed" format.  It can be written down, typed, saved on a disk, recorded, filmed, painted, or sculpted.  Published and distributed works are usually registered with the U. S. Copyright Office at the Library of Congress, however, a work does not have to be registered to be protected by copyright law.  Copyright lasts for the life of the author or artist plus 70 years.  Eventually, when copyright on a work expires, it passes into the public domain.  If you are are using material from a work in the public domain, you should still cite your source. Why is copyright important?  It gives owners the exclusive right to make decisions about their intellectual property.  Copyright owners decide how the work is sold, distributed, reproduced (that means copying!), performed, or displayed.  Usually these decisions are spelled out in a contract.  A copyright owner can sue anyone who infringes on their copyright.  Copyright infringement includes plagiarism, the attempt to pass off another person's work as your own, without giving them credit.  Plagiarism is derived form the Latin word meaning "man-stealing" or "kidnapping."  Students should credit their sources by citing them.  (See the "Bibliography Help" section of the Library home page for specific examples of how to cite different formats.)