"Open Educational Resources are broadly considered to meet the “5Rs Framework,” meaning that users are free to:
(Defining the "Open" in Open Content and Open Educational Resources, http://opencontent.org/)
Why use OERs?
"OER is consistent with UNESCO’s constitutional commitment to “the free exchange of ideas and knowledge”. Learning materials freely available for adaptation and re-purposing can expand access to learning of better quality at lower cost. The rapid expansion of technology-mediated approaches to deliver learning worldwide has accentuated the sharing and relevance of OER and amplified this global phenomenon."
("What is the story behind Open Educational Resources?", UNESCO.org)
What is the difference between OER and Open Access Publishing?
"Open access publishing is typically referring to research publications of some kind released under an open licence. OER refers to teaching and learning materials released under such a licence."
(What is the difference between OER and Open Access Publishing? OER Knowledge Cloud, n.d.)