Answer:
Open educational resources (OER) are educational materials that are distributed at no cost with legal permission for the public to freely use, share, and build upon the content.
The Hewlett Foundation defines OER as “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 re-purposing 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”