This document provides an overview of copyright law in the United States. It defines copyright as protection for original works of authorship under title 17 of the U.S. Code. Infringement occurs when someone violates the exclusive rights of the copyright owner without permission. Certain materials like facts, ideas, and works in the public domain can be used freely. Fair use allows limited use of copyrighted works for purposes like criticism or research. Creative Commons licensing enables sharing of some works within certain conditions. Permission is required to use a work beyond fair use or Creative Commons terms.