Definition of Open Educational Resources,
"Open Educational Resources are teaching, learning, and research resources that reside in the public domain or have been released under an intellectual property license that permits their free use and repurposing by others. OER include full courses, course materials, modules, textbooks, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge." ~ William & Flora Hewlett Foundation
Defining the "Open" in Open Content and Open Educational Resources
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 everyone with free and perpetual permission to engage in the 5R activities:
From https://opencontent.org/definition/
"An Introduction to Open Educational Resources" by Abbey Elder is licensed under a CC BY 4.0 International license: https://creativecommons.org/licenses/...