What is a preprint or author manuscript?
Most publishers allow some version of the author's manuscript to be submitted to an institutional research repository, and some of the more generous publishers allow the publisher version to be deposited. As well, you can deposit the published version of an article published in an Open Access journal. There are different versions of an author's manuscript which are described below:
Preprint: The "pre" in preprint means pre-refereeing (i.e., unrefereed) research papers, almost all of them prepared for submission to refereed journals (or refereed conference proceedings) for refereeing.
Postprints: The "post" in postprint means post-refereeing (i.e., refereed, revised, accepted final drafts of) research papers, all of them appearing in or soon to appear in refereed journals (or refereed conference proceedings). Note that the author's final draft (author's final version) will have the same content as the publisher's final version, but the author's final version has far fewer restrictions on it than the publisher's version of record. For example, the author's final version could be deposited in Summit, but the publisher version could not be deposited.