The U.S. Copyright Office states copyright is: "A form of protection provided by the laws of the United States for "original works of authorship", including literary, dramatic, musical, architectural, cartographic, choreographic, pantomimic, pictorial, graphic, sculptural, and audiovisual creations."

Copyright is a legal protection for authors and creators.

The authority to regulate copyright lies with Congress, per the U.S. Constitution, Article 8, Section 1, Clause 8: "To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;" Two key ideas are present in this text:

• "Promote the progress of science and useful arts"

  This brief phrase sets a foundational purpose for copyright laws and interpretations of those laws. Copyright law gives authors and creators what has been called a "limited economic monopoly" on their works, but that "economic monopoly" is not the purpose. The purpose is to promote science and art. However, the Copyright Clause in the U.S. Constitution does not describe exactly how an economic monopoly on creative works accomplishes that purpose, and so a complex of copyright laws, revisions of laws, and court cases have sought to interpret that intention.

• "Securing for limited times"

  Copyright has limits, which has been defined by subsequent copyright laws like the Copyright Act of 1790, Copyright Act of 1978, the Sonny Bono Copyright Term Extension Act and Digital Millenium Copyright Act of 1998, and other revisions. Numerous court cases have refined interpretation of these acts over the years.

  See this timeline of the history of copyright in the United States from the Association of Research Libraries for more information on copyright acts, revisions, and key court cases. 

Title 17 of the U.S. Code concerns copyright. 17 U.S.C. § 102 states:

(a) Copyright protection subsists, in accordance with this title, in original works of authorship fixed in any tangible medium of expression, now known or later developed, from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device. Works of authorship include the following categories:

(1) literary works;
(2) musical works, including any accompanying words;
(3) dramatic works, including any accompanying music
(4) pantomimes and choreographic works;
(5) pictorial, graphic, and sculptural works;
(6) motion pictures and other audiovisual works;
(7) sound recordings; and
(8) architectural works.

What is not protected under copyright?

• Ideas, procedures, methods, systems, processes, concepts, principles, or discoveries
• Works that are not fixed in a tangible form (such as a choreographic work that has not been notated or recorded or an improvisational speech that has not been written down)
• Titles, names, short phrases, and slogans
• Familiar symbols or designs
• Mere variations of typographic ornamentation, lettering, or coloring
• Mere listings of ingredients or content