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Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how likely a website is to 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.

Thanks for valuable answer, Ross. Please have a look at https://moz.com/community/q/subdomain-and-nofollow-backlinks-are-used-to-calculate-the-domain-authority I need answer from Moz official. Because I think the calculation of Google and Moz are different in Link building. So, I want to know it eagerly.