Open Copyright License
"An “open copyright license” is an irrevocable copyright license which grants the following permissions to everyone at no cost: permission to reuse the artifact (e.g., publicly display or perform), permission to copy and redistribute the artifact (e.g., share), permission to revise the artifact (e.g., translate or localize), and permission to remix the artifact with other artifacts (e.g., mashup or collage). This grant of permissions may come with restrictions. For example, a license may restrict these permissions to (1) those who agree to attribute the author of the OER when exercising the permissions, (2) those who agree to relicense any derivative works based on the OER under precisely the same license, or (3) those who agree to exercise the granted permissions in only noncommercial ways. The Creative Commons BY, BY-SA, and BY-NC-SA licenses are examples of open licenses.
“In the public domain” means that, while the nature of the artifact qualifies it for copyright protection, the artifact is not subject to copyright restrictions.
A benefit of defining an “open educational resource” in terms of copyright status is that the definition implies that all OER belong to the universe of copyrightable things. This explicitly precludes ideas, concepts, methods, people, places, events, and other non-copyrightable entities from being OER. (This helps us avoid some of the nonsense that went on with “learning object” definitions.)
For many high-level purposes this definition may be sufficient. However, there is a significant amount of nuance hiding beneath this quick-and-dirty definition. While adopting a blunt definition of OER may be common practice, understanding the underlying nuance would likely be valuable. One way of exploring this additional meaning is asking, “What would the ideal OER look like?” (http://opencontent.org/blog/archives/2015)