What is open access?
A popular definition in Peter Suber's article summarised that "Open-access (OA) literature is digital, online, free of charge and free of most copyright and licensing restrictions".
Open Access is a growing worldwide movement:
Open Access in Aotearoa - a guide from Creative Commons Aotearoa New Zealand (PDF, 12 pages)
Benefits of Open Access:
Budapest Open Access Initiative (Feb. 14, 2002)
Bethesda Statement on Open Access Publishing (Apr. 11, 2003),
Open Access 2020 - OA2020 is an initiative under the umbrella of the Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities, which has been embraced by more than 540 signatory institutions.
The Tasman Declaration on Open Research (March 2013) "recommends key actions through which New Zealand and Australia can coordinate and advance their respective open approaches to research towards greater economic, societal, and environmental impact."
Green OA often refers to research papers deposited in a digital archive/repository by authors. There are two types of repositories:
Some universities also publish Green OA journals.
Gold OA: peer reviewed articles published in online open access journals that are free to the public. Author or the author's institution is usually required to pay an article processing charge (APC) fee in order to publish articles in OA journals.
Hybrid OA - some subscription-based journals are "hybrid" with a portion of articles being open access and the rest of articles are available to subscribers only. Authors of accepted articles in the hybrid model are often required to pay an article processing charge (APC) fee.