Page Authority (PA)
Page Authority (PA) is Moz's 1-to-100 score predicting how well a specific page (not the whole site) will rank in search.
PA is the page-level companion to Moz's domain authority (DA), built from the same link-based, machine-learning model but focused on the links and signals pointing at one URL. It exists because a single strong page on an otherwise modest site can rank well, and a weak page on a powerful domain can underperform.
When prospecting for links, PA helps you judge the value of the exact page you would appear on, in the same way Ahrefs' url rating (UR) does. A page with high PA generally has more accumulated link equity to share, making a contextual link from it more valuable than one from a thin, freshly published page.
Keep the standard caveat in mind: PA is a Moz prediction, not a Google ranking factor, and it can be skewed by manipulative linking. Cross-check it against the page's actual organic traffic and topical relevance, since a high PA on an irrelevant page does little for your own rankings.