PA is page authority. It is the value of a webpage as assessed on the basis of several factors including age of the content, popularity reflected by traffic and the quality of backlinks to the particular page, outbound links and the level of trust. Page authority is similar to domain authority in one way. Both indicate popularity, for a webpage and a website respectively. However, domain authority does not necessarily mean the authority of a page will be higher. Likewise, high page authority does not guarantee better domain authority. Multiple pages having higher authority do contribute to better domain authority metric. PA or page authority metric is the score assigned to a particular webpage.
PA or page authority can be improved by content creators and links are the most important attributes of a webpage for it to have a good page authority metric in search engine optimization. Page authority is not search engine ranking. It does not directly influence the ranking assigned by search engines like Google. However, the page authority metric is a reliable indicator that can help search engine optimization experts improve their strategy to rank a page and a website higher on Google search engine result pages.