Open Educational Resources are teaching, learning and research materials in any medium – digital or otherwise – that reside in the public domain or have been released under an open license that permits no-cost access, use, adaptation and redistribution by others with no or limited restrictions.
Why Open Education Matters - a brief introduction of the idea behind OER.
How can OER impact students? They save students money!
The terms "open content" and "open educational resources" describe any copyrightable work (traditionally excluding software, which is described by other terms like "open source") that is licensed in a manner that provides users with free and perpetual permission to engage in the 5R activities:
Source: Text and image by David Wiley, opencontent.org, published under a Creative Commons Attribution 4.0 license