"Open Education Resources (OER) are teaching, learning, and research materials that are either (a) in the public domain or (b) licensed in a manner that provides everyone with free and perpetual permission to engage in the 5R activities." Creative Commons
The 5Rs are permissions assigned to copyrighted works. The more Rs attributed to a work, the more "open" the work is.
This material is based on original writing by David Wiley, which was published freely under a Creative Commons Attribution 4.0 license athttp://opencontent.org/definition/ (Links to an external site.)