Open Access (OA) is implemented internationally through two complementary approaches:
The first approach, known as the “golden road” (golden route), allows Open Access through the publication of articles in journals that provide free access to their content. This can be achieved either by charging authors or their institutions for peer review and publication, or by making the articles freely accessible to everyone at no cost.
The second approach, the “green road” (green route), is the more widespread method and is achieved through self-archiving.
Authors provide Open Access to their published works by uploading digital copies (eprints) to open repositories for public access. This can be done either before peer review (preprint) or after acceptance and incorporation of reviewers’ comments into the final text (postprint).
Digital copies of publications must be deposited in institutional repositories and accompanied by metadata, so that they are discoverable on the global web through protocols such as the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). This allows them to be searched via specialized search engines or general search engines like Google.