Open Educational Resources are publicly accessible materials useful for teaching, learning, and assessing as well as for research purposes. They are openly available for anyone to use and, under some licenses, to re-mix, improve and redistribute.
UNESCO defines OERs as "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".
David Wiley, world expert on open content, states that "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 either (1) in the public domain or (2) licensed in a manner that provides users with free and perpetual permission to engage in the 5R activities."
Materials licenced as OERs generally provide users with free access and permission for the following activities:
Due to their nature, OERs provide the following advantages to their users: