"Open Access is the free, immediate, online availability of research articles coupled with the rights to use these articles fully in the digital environment. Open Access ensures that anyone can access and use these results—to turn ideas into industries and breakthroughs into better lives." ~SPARC (the Scholarly Publishing and Academic Resources Coalition)
"Open Access seeks to return scholarly publishing to its original purpose: to spread knowledge and allow that knowledge to be built upon. Price barriers should not prevent students (or anyone) from getting access to research they need. Open Access, and the open availability and searchability of scholarly research that it entails, will have a significant positive impact on everything from education to the practice of medicine to the ability of entrepreneurs to innovate." Right to Research Coalition
In OA lingo, a “preprint” is any version of an article prior to peer review, such as a draft circulating among colleagues or the version submitted to a journal. A “postprint”is any version approved by peer review. The scope of green OA deliberately extends to both preprints and postprints, just as the function of gold OA deliberately includes peer review. ~ pg. 100 from Open access by Peter Suber
An ever-increasing amount of scholarship is being published openly, either via the publisher’s website or through another online resource, including open access repositories, or author/academic networking websites. Some of these OA publications will be the final published version, but often the publisher permits the public sharing of the accepted manuscript (a version including editing marks from peer-review but lacking the publisher branding or typesetting) or the pre-print (submitted manuscript pre-peer review).