Open Access models

There are several ways of doing Open Access, depending on whether or not you publish (and therefore go through a publishing process), and depending on whether or not you pay to make a publication accessible.

There are different models of Open Access: 

The green Open access :  is the self-archiving of publications. This involves depositing (and not publishing) a publication in a repository (institutional, disciplinary or other) for scientific publications and making it open access. It's self-archiving, then, since it is generally the author him/herself who takes the step of depositing. The term ‘deposit’ is used rather than ‘publication’, as there is no need to go through a publisher. This model is generally free for both the author and the reader. The author retains his or her copyright in the work and may be free to publish it if he or she wishes.

Gold open access :  the publisher asks the author who desires to publish in open access to pay a fee (APC for Article Processing charge or BPC for book processing charges). Once published, the work is freely accessible to anyone.

Diamond open access : is a way to immediatly publish without any fees for the author nor the reader

Hybrid models : some commercial publishers offer publication models that charge both the author for making their work available in open access (APC or BPC) and the readers (in the form of a subscription) for access to content that is not in open access.