Copyright is a form of protection provided by the laws of the United States for original works of authorship, including literary, dramatic, musical, architectural, cartographic, choreographic, pantomimic, pictorial, graphic, sculptural, and audiovisual creations. “Copyright” literally means the right to copy. The term has come to mean that body of exclusive rights granted by law to authors for protection of their work. The owner of copyright has the exclusive right to reproduce, distribute, and, in the case of certain works, publicly perform or display the work; to prepare derivative works; in the case of sound recordings, to perform the work publicly by means of a digital audio transmission; or to license others to engage in the same acts under specific terms and conditions. Copyright protection does not extend to any idea, procedure, process, slogan, principle, or discovery.
http://www.copyright.gov/circs/circ1a.html
Using a protected work without permission of the copyright holder is an infringement of copyright. There are, however, certain exceptions to the exclusive rights of the copyright owner, and one that is particularly relevant to academic institutions is the doctrine of fair use. This doctrine allows the limited use, under certain circumstances, of small portions of copyrighted materials for non-commercial educational or research use without first seeking permission of the copyright holder. However, even when a work is used with permission or appropriately used under fair use guidelines, the source must be properly acknowledged. Failure to do so is likely to be an act of plagiarism. Another thing to bear in mind, especially in regard to electronic resources, is whether their use is governed by licensing agreements and contracts.
http://guides.mclibrary.duke.edu/copyright