Open Educational Resources are teaching, learning, and research resources that are free of cost and access barriers, and which also carry legal permission for open use.
They are considered Open Educational Resources if they follow the 5Rs framework created by David Wiley.
These 5Rs are:
They are either in the public domain or licensed through Creative Commons licensing so that materials can be adapted to suit the needs of the user, whether that be students or faculty. Pay close attention to what licensing an OER you are using falls under, to better understand what is allowed and what is not.
For more information on Open Educational Resources check out the links below.