Mitchell, Charlie, ed. Theatrical Worlds. (Gainesville: University Press of Florida, 2014). ISBN 978-1-61610-1660-4.
UNESCO provides this definition: "Open Educational Resources (OER) are teaching, learning or research materials that are in the public domain or released with intellectual property licenses that facilitate the free use, adaptation and distribution of resources." This means that OER are freely available online for anyone to use, reuse, and share. Most creators share their OER under Creative Commons (or similar) licenses. Under these licenses, creators keep copyright ownership but let users copy, distribute, and remix the OER for their own purposes.
From the Emory Libraries website, "Using Open Education Resources (OER)."