Copyright allows authors to benefit from their work for a limited period of time. Copyright law has changed many times in the United States and the the intricacies of the law are so complicated, only a copyright lawyer can understand them. When you publish open access, the author retains the copyright to their work, but gives permission its use under a Creative Commons license.
Creative Commons is a non-profit intellectual property licensing organization. The licenses are free and allow authors to protect their work with a variety of different restrictions:
Different licenses can be mixed and matched to protect your work. See the different license types here: https://creativecommons.org/licenses/
Fair Use is a set of exceptions in copyright law which allow people other than the copyright holder to use copyrighted material. This allows other authors to quote a work, or educators to use material without having to get permission from the copyright holder first. The outline for fair use is intentionally blurry in order to protect both the copyright holder and the users of materials. The Fair Use Checklist includes more detailed guidelines.
Gold Open Access is when the final, published version of an article is available, without restrictions, to the public.
Journals that provide gold open access can be funded in a variety of ways, including: being subsidized by an institution or government; charging the author a fee to cover the costs of publishing; advertising revenue; or a freemium model.
The phrase Green Open Access refers to an author sharing a copy of their article via a repository or website after publishing in a traditional journal.
In many cases, the publisher of the journal will have language in the author contract that states what version of the article can be shared as well as how soon after publication. For example, sharing a pre-print version of an article is generally acceptable at any time, while the accepted manuscript (the version that will actually be published) will most likely have some sort of embargo period before you're allowed to share it.
It is important to carefully read contracts between you and the specific journal you are publishing in. Even journals published by the same company might have differing contractual rules regarding Green OA.
Paywalls are programs that restrict access to content to paying subscribers only. Subscribers are asked to create accounts and login credentials. Most databases offered through the University Libraries fall under this concept of a paywall which is why you are required to login with your WMU credentials. Students, faculty, and staff of the WMU community do not directly pay for the databases subscription but the University Libraries does. through funds acquired through tuition and student fees. The login process recognizes you as a "paying" subscriber.
Attribution: Mark Bilby, California State University- Fullerton Library. Licensed under a CC-BY License