In the United States and many other places, a copyright is automatically granted to the author of original work. Trademarks and patents need registration.
Registration of copyright refers toRegistration instructions for the United States can be found at http://www.copyright.gov/forms/
the act of registering the work with
the United States Copyright Office,
which is an office of the Library of
Congress. As the United States has
joined the Berne Convention,
registration is no longer necessary to
provide copyright protection. However,
registration is still necessary to
obtain statutory damages in case of
Note that in the U.S. there is a big difference between the legal protections you get with an automatic copyright, as opposed to what you get when you register with the copyright office.
If you don't actually register the copyright you can't collect attorney fees or statutory damages for copyright infringement. In practice, those limitations make it almost impossible to sue someone for copyright infringement unless you register the copyright first. See a lawyer for details.