So, if copyright is now automatically bestowed at the time of artistic creation, why do people apply for copyright registration?
Copyright rules vary according to country, and some countries require works be registered before they have the protection of copyright. What the United States Copyright Office does is not grant copyright, although that has been part of its purpose in the past. What it does is register copyright. A registered copyright bestows legal benefits that merely holding a copyright does not.
To learn more about registration of copyright, read The Steps Involved in Applying for a Copyright.

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The United States Copyright Office website says:
Registration establishes a public record of the copyright claim. Before an infringement suit may be filed in court, registration is necessary for works of U.S. origin. If made before or within five years of publication, registration establishes prima facie evidence in court of the validity of the copyright and of the facts stated in the certificate. If registration is made within three months after publication of the work or prior to an infringement of the work, statutory damages and attorney's fees will be available to the copyright owner in court actions. Also, registration allows the owner of the copyright to record the registration with the U.S. Customs Service for protection against importation of infringing copies.
Infringement occurs when there is unauthorized reproduction of a copyrighted work. There are situations where portions of copyrighted works can be used by other people, covered by the doctrine of fair use. Fair use does not have an explicit definition, but use is considered on a case-by-case situation when infringement of copyright is claimed.
Infringement affects the potential market for or value of the copyrighted work.
In paraphrase of Title 17, Chapter 1, section 107 of the United States code, which covers copyright law, fair use takes four factors into consideration:
- purpose and character of use;
- the nature of the original;
- the amount and substance of what is used in relationship to the whole work;
- whether the use of the work was detrimental to the value or saleability of the work.
People who want to use portions of a copyrighted work need to evaluate whether they are making fair use of the material or are infringing. They must also make attribution of the source, or they are plagiarizing.