The copyright is, literally, the right to copy something. Under current U.S. copyright law this right belongs to the creator of an original work of authorship, and it exists from the moment the work is fixed in tangible form. The copyright has been recognized in law for hundreds of years. In the United States, the U.S. Consititution specifically recognizes the copyright (along with the patent right) and is the root of U.S. copyright law. Most nations in the world also recognize the copyright and protect it in law.
The broad terms “work of authorship” and “fixed in tangible form” are difficult to define concisely; the ranges of their implications are covered elsewhere in these pages. In short, the author, artist, creator, or designer (the list is long) who records on paper, canvas, stone, film, optical disc, or computer chip (the list is long) an original, creative work in a form that can be viewed, heard, or otherwise perceived by others, either directly or with the aid of a machine, owns a copyright in that work. This right is the exclusive right to make and distribute copies of the work, including the exclusive right to authorize others to make and distribute copies of the work, both in the same form as that in which the work was originally fixed and in any other form in which the work may be fixed. That last is important, especially in these times when almost anything can be endlessly and easily reproduced and distributed by means ranging from photocopiers to the Internet.
Although a work is protected regardless of the medium of expression onto or in which it may be copied, it is essential to understand that the copyright in a work is strictly limited to original, creative expression, only. In short this means the copyright applies to the telling of the story and not to the story, and to the photograph of the mountain but not to the mountain. That is, copyright protection does not extend to the ideas behind the work or to any ideas, methods, or systems put forth by it, nor to any articles, devices, or events described by it, and not to facts recounted by or contained in it. Further, the extent of the copyright is limited in its duration, in its scope (for instance, under the doctrine of “fair use”), and by such lawful accomodations of practical reality as compulsory licensing, among other limitations.
The most basic limitation, however, is the limitation to that expression which is “fixed” in a form that others may perceive. Simply stated, this means that your idea for, say, the next great American novel gives you no rights in the novel until you actually write the novel, regardless of how perfectly or completely formed the novel may be in your mind. If you write a synopsis or a treatment of your novel, you may claim copyright in the expression that comprises the treatment, itself, but you still have no right in the proposed story, or in the planned novel, or in any other embodiment (movie, ballad, or video game, for example) of the characters, scenes, plot, or other story elements described in the treatment. If you write a chapter, you may claim copyright in the chapter, as far as it goes, but still not in the novel or TV mini-series that may or may not follow from it.