Copyrights protect creative expression in form of writing, recordings, artwork, films, software, and architecture. Copyrights confer the exclusive right to reproduce, display, perform, distribute, market, or sell the creative work, as well as to prepare adaptations or derivative works, or to authorize others to do so.

In order to be protected, a creative work must be original, fixed in a tangible medium of expression, and involve a minimum of creativity beyond mere facts and ideas. While fixation and minimum creativity are usually easily met, originality is of course a function of similarity to existing works. A registrability screening search looks for such similar existing works.
Although a copyright arises automatically upon fixation of a work in a medium, there are advantages to registering your work with the U.S. Copyright Office. If registration occurs within a certain time period, it may later make it easier to sue a potential infringer. Along with the appropriate forms, it may be necessary to deposit samples of the creative work for which copyright protection is sought.
Infringement may be found if the original work was independently created and sufficiently creative, and if there is substantial similarity between the two works. An action for infringement may fail if the offending work was the product of independent conception, falls under a fair use exception, or permission was given to use the work.
A copyright license agreement is an agreement in which the entity holding the copyright (the licensor) gives another entity that desires to use the copyright (the licensee) permission to do so in exchange for a payment or other compensation, called a royalty. The royalty may be one-time or ongoing, or a combination thereof. An assignment transfers all rights to the work, including reproduction, display, performance, distribution, and derivative works, whereas a license transfers only some of the rights to the work.