Open access (OA) refers to freely available, digital, online information. Open access scholarly literature is free of charge and often carries less restrictive copyright and licensing barriers than traditionally published works, for both the users and the authors.
While some OA publishers require authors to pay page charges to help defray the cost of publishing, OA is not vanity publishing or self-publishing since legitimate OA publishers still submit authors to the same rigors of peer review as traditional academic publishers. For more information, see Peter Suber's overview of Open Access: http://legacy.earlham.edu/~peters/fos/overview.htm.
Green OA publishing refers to the self-archiving of published or pre-publication works for free public use. Authors provide access to preprints or post-prints (with publisher permission) in an institutional or disciplinary archive such as eCommons@Cornell and arXiv.org.
Gold OA publishing refers to works published in an open access journal and accessed via the journal or publisher's website. Examples of Gold OA include PLOS (Public Library of Science) and BioMed Central.
Image: Opensource.com, http://tinyurl.com/l7y66vo
There are many discipline-specific as well as multi-disciplinary open access journals. Choose journals for publication carefully; review the other pages in this guide for more information on what to look for in a journal, or contact your librarian for help.