Open Educational Resources (OER) are teaching, learning and research materials in any medium that reside in the public domain or have been released under open licenses that permits no-cost access, use, adaptation and redistribution by others.
OER can be freely downloaded, edited, and shared, and have the following characteristics known as the 5Rs:
Open Access (OA) describes research literature that is free and available "on the public internet, permitting any users to read, download, copy, distribute, print, search, or link to the full texts of [research] articles, crawl them for indexing, pass them as data to software, or use them for any other lawful purpose, without financial, legal, or technical barriers other than those inseparable from gaining access to the internet itself," according the Budapest Open Access Initiative.
"The only constraint on reproduction and distribution and the only role for copyright in this domain should be to give authors control over the integrity of their work and the right to be properly acknowledged and cited.”
The OA model includes the following components:
Remember, while OA is "free" to access, there are still costs for the author to publish the work.