Open Access is the practice in which published material, generally articles, are shared freely on the internet without restrictions. In the case of academic articles, open access (OA) stands in stark contrast from the traditional model of publishing, which requires readers/institutions to subscribe in order to gain access to an article.
In open access journals, the author usually pays an article processing change (APC) to cover the cost of publishing.
There are many variations of open access publishing models, including:
Gold – articles in fully open journals, like PLOS One, in which all articles are published through article processing charges and the entire journal is open to everyone in the world
Hybrid – authors can choose to pay an APC to make an article available to everyone around the world even though most of the other content in the journal is subscription only and even if the institution pays for a subscription to that journal
Green – allows self-archiving of the article in a repository such as ResearchGate or NAU's digital repository OpenKnowledge@NAU, though the published article is in a traditional journal that requires a subscription to access
The DOAJ Seal is awarded to journals that achieve a high level of openness, and adhere to best practices and high publishing standards, though it is not an indication of the academic quality of a journal.