Open Educational Resources (OER) are educational materials that are licensed to be freely available for teachers and students to use, adapt, share, and reuse.
Examples of OER include learning content (such as lesson plans, assignments, textbooks, exams, and videos) as well as tools for learning (like software, homework systems, interactive diagrams, and more)
The "5 R's" of OER
Retain:the right to make, own, and control copies of the content
Reuse: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)
Revise:the right to adapt, adjust, modify, or alter the content itself (e.g., translate the content into another language)
Remix: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)
Redistribute: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)