Copyright is a legal device that provides the creator of a work of art or literature, or a work that conveys information or ideas, the right to control how the work is used. Those rights include:
An author's copyright rights may be exercised only by the author or a person or entity to whom the author has transferred all or part of her rights. If someone wrongfully uses the protected material, the copyright owner can sue and obtain compensation for any losses suffered.
For a complete discussion of copyright law, see The Copyright Handbook, by attorney Stephen Fishman.