The Domain authority (also referred to as thought leadership) of a website describes its relevance for a specific subject area or industry. Domain Authority is a search engine ranking score developed by Moz.[
This relevance has a direct impact on its ranking by search engines, trying to assess domain authority through automated analytic algorithms. The relevance of domain authority on website-listing in the SERPs of search engines led to the birth of a whole industry of Black Hat SEO providers, trying to feign an increased level of domain authority.
Domain Authority is calculated by evaluating multiple factors, including linking root domains and total number of links, into a single DA score. This score can then be used when comparing websites or tracking the "ranking strength" of a website over time.
The ranking by major search engines, e.g., Google’s PageRank is agnostic of specific industry or subject areas and assesses a website in the context of the totality of websites in the Internet. The results on the SERP page set the PageRank in the context of a specific keyword. In a less competitive subject area, even websites with a low PageRank can achieve high visibility in search engines as the highest ranked sites that match specific search words are positioned on the first positions in the SERPs.