Open Access (OA) content, which includes open scholarly articles, open data, open research, open education, is digital, online, free of charge, and free of most copyright and licensing restrictions.There are different ways of engaging with open access
There are two primary vehicles for delivering OA to research articles, OA journals ("Gold OA") and OA repositories ("Green OA"). The main difference between them is that OA journals conduct peer review and OA repositories do not. Institutional Repositories can contain peer-reviewed journal articles that are published elsewhere. They can also contain pre-prints and post-prints of scholarly published articles.
There is also Gratis OA and Libre OA. Gratis OA removes no permission barriers and Libre OA removes one or more permission barriers. (Both of them remove price barriers.)
Jonathan Eisen, Nick Shockey and Jorge Cham, SPARC and PhD Comics, 2013.
"Open Access Explained" by Jonathan Eisen, Nick Shockey and Jorge Cham, SPARC and PhD Comics, 2013. is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Open Access Publishing (Gold): The characteristics of open access publishing are akin to traditional publishing, by which an author submits a work to be peer reviewed and is published at no cost for others to read. Costs to fund the publication process may be assessed to the author through article processing charges, although many publishers charge no fee.
Open Access Self-Archiving (Green): Green open access involves the self-archiving of research published through traditional journals. A variety of platforms are available for researchers to self-archive their work, including disciplinary repositories (e.g. ArXiv or PubMed Central) and institutional repositories (e.g. Scholarship@Claremont) hosted by universities and organizations.
Why the Colors? - Understanding Gold and Green Open Access
A brief video from the University of Minnesota Libraries explaining gold and green open access, including a review of the advantages and disadvantages of each.