Copyright registration is the process for filing a copyright with the U.S. Copyright Office created by § 408 of the Copyright Act of 1976. Registration consists of sending to the Copyright Office a copyright application, fee, and deposit of the work, which is separate from the deposit requirement in § 407 for the Library of Congress.
A person gains copyright protection over a work at its formulation under § 102, but a person must register with the Copyright Office before bringing a civil action for copyright infringement under § 411. In the 2019 case of Fourth Estate Public Benefit Corporation v. Wall-Street.com, LLC, the Supreme Court held that registration and the right to bring a civil suit occur when the Register of Copyrights actually registers the work, not when the Copyright Office receives the registration.
[Last updated in June of 2021 by the Wex Definitions Team]