"Open Educational Resources (OER) are high-quality, openly licensed, online educational materials that offer an extraordinary opportunity for people everywhere to share, use, and reuse knowledge. They also demonstrate great potential as a mechanism for instructional innovation as networks of teachers and learners share best practices." - The Hewlett Foundation
According to the Open Education Handbook OER need to meet the "5Rs Framework." This framework outlines that resources are free, and that users have the legal right to:
OERs are not just textbooks, other common resources include:
Open educational resources (OERs) are materials that are free of charge, and free of most copyright and licensing restrictions.
“Many researchers release their previously unpublished work under a Creative Commons (CC) license, that allows you to authorize some uses of your work, while preventing others... For more information, please visit the websites for Creative Commons.” (Open Access, Montclair State University, http://montclair.libguides.com/openaccess)
OERs can be used to customize course materials and are often used to save students the cost of buying an expensive textbook.
The following "Quick Guide to Open Educational Resources" is from Georgia State University Library at http://research.library.gsu.edu/openeducation