"Open Educational Resources are 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."
Larry Kramer, Hewlett Foundation
Open Educational Resources, 4/4/2019
OERs are part of the larger Open Content movement. Open Content is often licensed through the Creative Commons. These licenses allow permissions known as the 5Rs: Retain, Reuse, Revise, Remix, and Redistribute. Not every Creative Commons allows every permission, so it is a good idea to familiarize yourself with the 6 Creative Commons (CC) licenses.
Aside from the obvious cost-savings for students, instructor, and institution, using OERs (particularly Open Textbooks) can have multiple benefits in the classroom: