Fair use is a limitation on the exclusive rights of a copyright holder. If a proposed use meets the “fair use” criteria, a copyrighted work may be used without permission of the copyright holder. Section 107 of the Copyright Act states that the “fair use” of a copyrighted work, including reproduction for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. Not all educational uses are “fair.” Section 107 lists four factors that must be considered in determining whether or not a use is fair, consequently the result of a fair use analysis will vary depending on the facts of the situation. More at the CUNY Copyright Site.