“Open Access is the free, immediate, online availability of research articles coupled with the rights to use these articles fully in the digital environment. Open Access ensures that anyone can access and use these results—to turn ideas into industries and breakthroughs into better lives.” (SPARC)
OA is achieved through two primary channels: archiving (Green OA) or publishing (Gold OA). OA is completely compatible with peer review.
OA archiving is the intentional act by content producers to make copies of their works available in a freely-accessible digital archive or repository. Repositories may be affiliated with funding agencies or institutions, or may be subject-specific. Although archiving of the final published version is the ideal, most archived works are either preprints or postprints.
OA publishing shifts the costs of content creation and distribution away from subscribers. What this means is that OA published information is freely available to anyone worldwide with an internet connection - no subscription necessary. Instead of relying on subscriptions to subsidize publishing costs, those costs are covered by sponsorships or author-side fees, which may be covered by institutions or grant-funding organizations.
OA Gold - publishing
OA Green - archiving
Hybrid - article-level OA in traditional subscription access journals, usually for a fee
Preprint - version of a scholarly work submitted for peer review including only the original work of the author(s)
Postprint - also known as the author's final version, this version incorporates all changes from peer review, but it has not yet been copyedited and formatted for publication
Creative Commons - a nonprofit organization that creates licenses under which works are distributed with reuse permissions granted upfront
Addendum - attached to publication or copyright transfer agreements requesting additional author rights beyond those already granted by the publisher