Version of record
Also called: VoR, published version
The publisher's final, typeset, citable version of an article — the one page numbers and DOIs point at.
The version of record is what the journal considers published: copy-edited, paginated, assigned a DOI, and the target of any later correction or retraction notice. Everything else — preprint, accepted manuscript, proof — is a stage on the way to it.
Cite it when you can. If you only have access to an earlier version, use it and be explicit, because a quotation's page number and sometimes its wording will not match.
See also
PreprintA manuscript posted publicly before peer review, on a server such as arXiv, bioRxiv, medRxiv, or SSRN.Postprint (accepted manuscript)The version of a paper after peer review but before the publisher's typesetting — the version most repositories are allowed to host.DOI (Digital Object Identifier)A permanent identifier for a document — usually a journal article — that resolves to its current location no matter how many times the publisher moves it.Erratum and corrigendumPublished corrections to an article: an erratum for the publisher's error, a corrigendum for the author's.