Open access is usually referred to as "GREEN" or "GOLD".
GREEN is the ability to archive a work. This could be preprint or post print depending on the publishers terms. AxXiv and CurateND are examples of repositories. Many universities have institutional repositories for green open access archived works.
GOLD is the published version of the work freely available and hosted by the publisher. Gold articles may appear in open access journals or in 'hybrid' journals. In most cases Gold open access involves an author Article Processing Charge (APC). PLoS is an example of a Gold open access publisher.
Hybrid journals offer an option for authors of accepted articles to pay, up-front, to have their articles open access. These journals will have both non-open and open content. Libraries may find the hybrid model objectionable because their subscription is paying to access content that is open access.
Open access journals that follow the highest standards of open access publishing may carry a seal from the Directory of Open Access Journals (DOAJ). The seal reflects only best practices as a publisher, not a statement of quality on the content.
Article Processing Charges (APC): The cost to the author associated with publishing an article. Though most commonly associated with Gold open access traditional publishers may also have charges per page with additional charges for color slides and graphics.
Author Addenda and Publisher Agreement: the terms that an author agrees to when publishing an article or book. The agreement is what the publisher requests, the addenda details any changes the author has requested and the publisher has agreed to. The SPARC addendum is an example of additional rights an author can request.
Author Accepted Manuscript: This is the final draft, the version of an article that has been accepted for publication reflecting changes made during the review process. In the publishing cycle this is after a pre-print and before the publisher's PDF.
Copyright: A form of intellectual property covered by US Code Title 17. Copyright gives the owner of the copyright a set of exclusive rights for a period of time. In general, for works created today protection exists for the life of the author plus 70 years or, if owned by a company or organization 95 years from the date of publication.
Copyright Transfer: Copyright is intellectual property and like any other property it can be given or sold. It is not unusual for publishers to ask authors to transfer their copyright to the publisher. Covered by section 204 of the copyright law.
Creative Commons License: A means to retain copyright while proactively granting permission to reuse the work under specific conditions such as attribution.
Directory of Open Access Journals (DOAJ): An online direction that indexes and provides access to peer-reviewed open access journals.
Gold Open Access: The author pays, upfront, to have their article made open access. Gold open access articles are available to everyone immediately upon publication.
Green Open Access: The author is allowed to archive an article in a repository.
License: A license is a contract with terms describing the rights and obligations of the parties involved.
Exclusive license: the rights described in the contract are given to only one party.
Non-exclusive license: the same or similar rights may be granted to others. A Creative Commons license is an example of a non-exclusive license.
Open Access: content that can be accessed without a subscription or payment, not closed off by a paywall. SHERPA/RoREMO categorizes publisher open access policies using the following terms:
Green: Ability to archive pre, post or publishers PDF.
Blue: Ability to archive post-print or publishers PDF.
Yellow: Ability to archive pre-prints
White: Archiving not supported
Open Access Mandate: The requirement of a grant-funding organizations such as the NIH that the results of research funded by their grants be made open access.
Open Access Policy: An institutional policy that requires authors and researchers deposit a copy of their articles in a repository.
Post-print: The version of the article as reviewed and edited, the version that will be published. This is a confusing term and is sometimes used to describe the final, published version (post any formatting done by the publisher). In open access it is at least the accepted for publication version.
Pre-print: A article that has been submitted to a journal but has not yet gone through peer review and has not been accepted.
Publishing Processing Fees: fees associated with publishing Publishers, not just open access publishers, may have charges associated with publishing an article. Even publishers that do not charge for text may have charges for color graphs.
Public Access Mandate: The same as an Open Access Mandate, a requirement of a grant-funding organizations such as the NIH that the results of research funded by their grants be made open access.
Publisher PDF: This is the published version of an article, the version that is released by the publisher in its journal. This is the 'version of record' and may include the publishers' mark, page numbers, volume and issue and, date.
Repository: sites where authors can deposit copies of their works. Curate ND is an example of a repository.
Sherpa/RoMEO: A site that records the open access level (green, blue, yellow, white or, ungraded) of specific journals and publishers. The site also provides links (when possible) to the standard author terms.
Open Access is rapidly becoming the norm for grant issuing agencies and with good reason. They are not funding research to support promotion and tenure, they're supporting research for results and they want those results to be available quickly and without paywalls.
Not sure if a grant-issuing agency has an open access policy? Here are some tools but the easiest way to be certain is to Google the agency and open access, e.g. National Science Foundation open access policy.
ROARMAP provides a list of known funding agencies with l open access requirements that have registered their policies.
Sherpa/Juliet provides a search tool for open access policies. This list appears to be less complete than ROARMAP.
Tri-Agency Open Access Policy on Publications Covers Canadian Institutes of Health Research (CIHR), Natural Scienes and Engineering Council of Canada (NSERC) and, Social Sciences and Humanities Research Council of Canada (SSRC).