The term ‘open educational resource’ is defined by US Congress to mean, "(6) a teaching, learning, or research resource that is offered freely to users in at least one form and that resides in the public domain or has been released under an open copyright license that allows for its free use, reuse, modification, and sharing with attribution."
Affordable resources can be defined as teaching, learning, or research resources available and low cost to students, such as library materials or low-cost textbooks. True OERs are considered open and available at no cost to all users, following the 5Rs of openness.
The “5 Rs” is a framework that encourages educators to capitalize on the unique rights associated with open content. These rights include the ability to: