Open access publishing essentially means that a manuscript is freely available online, without any paywalls or restrictions pertaining to reuse of work communicated in the manuscript. This model of publishing is beneficial to all other stakeholders except publishers such as authors, readers, and funding agencies. Work that is freely accessible to the research community can help authors increase their citation count. Readers on the other hand can access high quality research without having to pay for it. And finally, a lot of funders are charities or philanthropic organizations who want their funds to be used for the benefit of the scientific community and society as a whole. However, open access publishing involve the payment of an article processing fee to publishers, which may sometimes be a drawback for researchers with limited funding. Currently, the publishing industry is in the midst of an open access revolution know as Plan S, which aims to give full and immediate, free online access to, and largely unrestricted use and re-use of scholarly publications.
Currently, there are two major classifications of open access- Gold Open Access and Green Open Access.
Gold open access involves the free and permanent accessibility of an article immediately after publication. It also involves the copyright of the article being retained by the author rather that handing it over to the publishers and most importantly it allows other researchers to re-use the published work, as long as the original paper/author is credited. Therefore, gold open access is not merely the free availability of the article but also fulfillment of other conditions mentioned above.
Green open access on the other had refers to the freedom given to an author to self-archive his own work. This can be done through deposition of their version of the manuscript (Not the version published by the journal) in a database. There are certain restriction in green open access such as, the copyright of the article remains with the publisher and there are restriction on the reuse of the reported work as well. There is also an embargo period specified by respective journals on the public release of the manuscript that is deposited in the database.
