Public access is not the same as open access. Public access applies to the requirement by NIH and other government funding agencies that peer-reviewed manuscripts that come from publicly funded research be made publicly available within 12 months of publication. In contrast, open access is immediate.
If you publish an article that arose from publicly funded research, you are probably responsible for ensuring that the peer-reviewed manuscript is deposited in an open archive (like PubMed Central) within a certain period of time from the date of publication. You do not have to pay an article processing charge in order to deposit that manuscript. Journal publishers must allow you to deposit that manuscript; some journals provide that service to their authors.
Articles available from PubMed Central (PMC) are provided by the respective publishers or authors. Articles and manuscripts in PMC usually include an explicit copyright statement. To see the copyright information, click the “Copyright and License information” link on an article record.
