Within the bounds of Creative Commons licensing there are 5 key points to consider when using OERs:
Reuse - Content can be reused in its unaltered original format - 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)
Retain - Copies of content can be retained for personal archives or reference - the right to make, own, and control copies of the content (e.g., download, duplicate, store, and manage)
Revise - Content can be modified or altered to suit specific needs - the right to adapt, adjust, modify, or alter the content itself (e.g., translate the content into another language)
Remix - Content can be adapted with other similar content to create something new- the right to combine the original or revised content with other material to create something new (e.g., incorporate the content into a mashup)
Redistribute - Content can be shared with anyone else in its original or altered format - 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)
OERs include a wide range of materials: assessments, assignments, books, case studies, courses, journals, primary sources, reference materials, simulations, tutorials, tests, and textbooks.
This material is based on original writing by David Wiley, which was published freely under a Creative Commons Attribution 4.0 license at http://opencontent.org/definition