A Copyright prevents others from using certain creative works. Copyrights are established to protect creative works from being copied.
The Protection of a Copyright
A copyright gives the owner of the copyright the exclusive rights to whatever is copyrighted. This means that the owner is the only person permitted to make copies, give out, sell, show, or act out that creative work. Additionally, the owner of the copyrighted work also has the exclusive right to making derivative works from the copyrighted work.
The Purpose of a Copyright
Copyrights give an incentive to people to create and share their works. If every expression of an idea could be stolen by other, what incentive would there be to create or share new expressions? Public policy encourages new ideas and the expression of new ideas, and therefore lawmakers have decided to give some protection to those expressions, and therefore incentive to create and share them.
Works that May be Copyrighted
So the next question is, what is a creative work? A creative work may relate to an idea. The idea itself may not be copyrighted. The expression of the idea may be copyrighted.
Many works will contain original, copyrightable expressions, as well as non-copyrightable expressions. Copyright laws permit the copyrighting of portions of expressions of ideas, so that those that are original and copyrightable will still be protected.
Works that are generally non-copyrightable are works that are public domain, works that are not original, common techniques, actual occurrences in history, and many others.
Example
For example, an author might write person attempting to find a job, interviewing, being rejected, and ultimately accepting a new job, as well as the trials and tribulations of the job. This author’s creative expression of the storyline and characters is protected matter. However, this author does not have an exclusive right to the idea, concept, or principle of this storyline. The more detailed portions of a fictional work are more likely to be protected matter than the more general portions.
A recount of factual events will receive less copyright protection than fictional stories.
The means of expression of facts and events, for example in a non-fiction book, are protected by copyright. However, another author is permitted to recount, in another way, the same facts and events.
The Merger Doctrine
However, when protected matter and unprotected matter both exist in a work, there is a possibility that the merger doctrine will apply. The merger doctrine allows an author to copy protected matter to the extent necessary if there is only one, or a few, ways of describing or depicting the unprotected matter. Otherwise, it would be difficult or impossible to express the unprotected matter.
Example
For example, a fish has scales, gills, fins, two eyes, a mouth, survives only in water, and swims. It would be nearly impossible to depict a fish without these characteristics. Therefore, similarities among depictions of drawings or paintings of fish, under the merger doctrine, cannot be the basis for finding infringement on the copyright. The expressive protected matter merges with the unprotected matter. Otherwise, copyright law would prohibit any drawings or paintings of fish.