Different levels of openness exist. Publisher policies largely dictate these and how published material is accessible. It does not always mean the work is in the public domain; in many cases, open access means the work has been assigned a license by its copyright holder granting permissions for others to reproduce and redistribute their work,
Gold OA refers to publications that are immediately 100% free and accessible to all. Some Gold OA journals require the authors to pay a fee to support this model read more under this guide's section on paying for open access.
Green OA refers to publications that are available as pre-prints or final peer-reviewed manuscripts, hosted in an institutional or subject repository. Still, the copyright of the final published manuscript may belong to the publisher. This model usually does not require authors to pay a fee; authors must discuss this option with their journal.
