This document summarizes U.S. copyright law and the concept of fair use. It outlines the four factors courts consider in determining fair use: purpose and character of the use, nature of the work, amount used, and effect on the market. It provides guidelines for educational fair use of text, images, audio, video and other materials. Educators are allowed to use copyrighted works for teaching for up to two years but must obtain permission for longer use. The document cautions readers to be aware of copyright law and only use brief portions of works as allowed by fair use.