U.S. copyright laws protect "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."
There are three main elements of this definition: (1) the work must be "original", (2) the work must be "fixed", and (3) the work must be an "expression", rather than an idea.
(1) "Original works of authorship"
- Include: books, photographs, music, drama, video, sculpture, software, multimedia, and databases.
- Mere alphabetical arrangement of facts alone do not warrant copyright protection.
(2) "Fixed medium"
- A work is fixed when "its embodiment in a copy or phonorecord, by or under the authority of the author, is sufficiently permanent or stable to permit it to be perceived, reproduced, or otherwise communicated for a period of more than transitory duration. A work consisting of sounds, images, or both, that are being transmitted, is 'fixed' for purposes of this title if a fixation of the work is being made simultaneously with its transmission".
- Works that have not been fixed in a tangible form of expression, (for example, choreographic works that have not been notated or recorded, or improvisational speeches or performances that have not been written or recorded) are not eligible for Federal copyright protection.
- Copyright protection does not "extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work."
- In the landmark case of Baker v. Selden, the Court reasoned that protection extended to the expression of the idea, not to the idea itself.