OER either reside in the public domain or are licensed under an open license (*). Broadly defined, an open license is a license that grants permission to use, re-use, and redistribute a work with few or no restrictions. Creative Commons licenses are most widely used by OER creators.
You may freely use materials residing in the public domain without any restrictions.
You may freely use materials released under the Creative Commons (CC) licenses as long as you follow the license conditions.
(*) Examples of other open licenses include open publication license and GNU Free Documentation License.
OER means that a resource is available free of cost and that five permissions (called the "5Rs") are also available free of cost.
These permissions include:
|Retain||Make and own copies|
|Reuse||Use in a wide range of ways|
|Revise||Adapt, modify, and improve|
|Remix||Combine two or more|
|Redistribute||Share with others|
Based on David Wiley's The Access Compromise and the 5th R ; CC BY