Creative Commons is a non-profit intellectual property licensing organization. The licenses are free and allow authors to protect their work with a variety of different restrictions:
Different licenses can be mixed and matched to protect your work. See the different license typse here: https://creativecommons.org/licenses/
Fair Use is a set of exceptions in copyright law which allow people other than the copyright holder to use copyrighted material. This allows other authors to quote a work, or educators to use material without having to get permission from the copyright holder first. The outline for fair use is intentionally blurry in order to protect both the copyright holder and the users of materials.
Click the video to watch Disney characters explaining fair use! The use of Disney is important because the company has a history of intimidating those who would take advantage of fair use with Disney content.
Copyright allows authors to benefit from their work for a limited period of time. Copyright law has changed many times in the United States and the the intricacies of the law are so complicated, only a copyright lawyer can understand them.
Click the link to read about the history of the U. S. Copyright Office. Part way down there is a helpful chronology of notable dates in copyright. http://www.copyright.gov/circs/circ1a.html
The Copyright Clearance Center (CCC) is a service that allows content users to pay content owners for their use of copyrighted content. In the case of books, publishers set a certain price per page with CCC and then users can fill out a form with CCC stating the intended use, how many pages they plan to use, and how many copies they plan to make. This video from CCC is jam packed with facts and figures about copyright.
See our Guide on Copyright Compliance for more information.