Page Authority (PA)is a metric, developed by SEOMoz, to predict the ability for a specific page to rank in search engines. Page authority uses a 0 to 100 logarithmic scale. A high Page authority score means your page has the potential to rank well in search engine results.
Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how well a website will rank on search engine result pages (SERPs). A Domain Authority score ranges from one to 100, with higher scores corresponding to a greater ability to rank.