Open educational resources (OER) are teaching, learning, and research resources that are created with the intention of being freely available to users anywhere. They may include, but are not limited to, textbooks, readings, multi-media files, software, assessment tools, and even entire courses. Most are covered by licenses that allow for using, re-mixing, and sharing.
the right to make, own, and control copies of the content
the right to use the content in a wide range of ways (e.g., in a class, in a study group, on a website, in a video)
the right to adapt, adjust, modify, or alter the content itself (e.g., translate the content into another language)
the right to combine the original or revised content with other open content to create something new (e.g., incorporate the content into a mashup)
the right to share copies of the original content, your revisions, or your remixes with others (e.g., give a copy of the content to a friend)
David Wiley, CC, March 2014, http://opencontent.org/blog/archives/3221