Copyright is a legal right, grounded in the United States Constitution, that gives the owner of copyright in a work the exclusive right to:
Copyright applies for a limited term. The length of that term depends on when the work was first created, whether or not it has been published, and whether the work was first published in the US or abroad.
Suffice it to say that for works created in the US today, copyright lasts for 70 years after the death of the creator and in the case of a corporate author (which could include works for hire), copyright lasts for 95 years from publication or 120 years from the date of creation, whichever expires first.
When the copyright term in a work expires, the work loses copyright protection and enters the public domain. See "Public Domain Defined" below.
To determine the copyright term for all other works, consult the Cornell University chart "Copyright Term and the Public Domain in the United States."
Original works, whether or not published, that exist in a tangible medium that can be touched, seen, heard, read and fall into one of the following categories are protected by copyright.
Copyright applies to a wide variety of works including, but not limited to:
These works are protected from the moment they are in a fixed format regardless of whether they contain a copyright notice or copyright has been registered.
Items not protected include, but are not limited to:
The following works are in the public domain and can be used by anyone for any legal purpose without permission.
Unless you are sure a work you find on a website falls into one of these four categories, you must assume the work is protected by copyright. See Using Copyrighted Material.