A copyright involves exclusive rights given to the creator of an original, expressive work (literary, musical, dramatic, architectural, etc.) that allow the owner to reproduce, copy, distribute, perform, display, or sell their work. These rights are usually extended for a specific time period. They protect the form of expression, not the subject matter of the work. In the United States, these rights are automatically granted to the creator, though formal registration of copyrighted works can provide additional benefits to the copyright holder. These rights are constrained by a series of limitations and exceptions, such as the first-sale doctrine (which allows you as a customer or second-hand bookstore, for instance, to resell a used book) and fair use doctrine (which permits the creative reuse of copyrighted works in many cases, including allowing comedians to parody the works of others in certain circumstances, for example).
source: MIT Press Open
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