Page Authority (PA) is a score developed by Moz that predicts how well a specific webpage is likely to rank on search engine result pages (SERPs). The score ranges from 1 to 100, with higher values indicating a greater ability to rank. PA is calculated using a variety of factors, including link profile data, and is based on a machine learning model. Unlike Domain Authority, which measures the strength of an entire domain, Page Authority focuses on individual pages, making it a useful metric for comparing the ranking potential of different URLs.