Usually, the URL in your address bar will be a persistent link. This can vary by journal, however, so always check the article record for anything labeled persistent link, permalink, stable link, link to this article, etc. When in doubt, Ask Us!
What's an Open Access Journal?
Peter Subar's nutshell definition: "Open-access (OA) literature is digital, online, free of
charge, and free of most copyright and licensing restrictions." OA journals may or may not be peer-reviewed; those in the DOAJ are.