Domain Rating is a score based on the measurement of the quantity and the quality of backlinks that a domain has acquired. Domain rating is a method utilized to understand how authoritative a site can be perceived by search engines and therefore improve ranking in the SERPs and the score falls on a 1-100 scale with 100 being the best.
When a quality domain links to another domain’s content through do-follow links it demonstrates a vote of confidence in that content, signaling to search engines that the content is authoritative, fresh, and relevant to the specific topic.
Another way to imagine a backlink and the signal that it sends is if you are to think of it as a referral. For example if you are interested in trying a new restaurant, you are likely going to ask a friend who often frequents local restaurants and went to culinary school. Since you trust your friend’s taste and culinary abilities any restaurant he/she recommends you trust will have quality food and service. This is the same concept receiving a backlink from a trustworthy and quality site to your own, it passes the signal of trust, relevance, and quality to a domain because it itself has those characteristics.
To establish a high domain rating, marketers should ensure that they are creating high quality, relevant, fresh, and authoritative content on their site so that other domains will want to link to it. There are many strategies and tactics that a marketer can execute to acquire backlinks and improve domain rating; including but not limited to, acquisition of lost and broken links, acquisition of competitors’ lost and broken links, guest post/blog, repurposing content.
There are many SEO companies, such as AHREFs, Moz, and SEMRush, that have created tools that determine a domain’s overall rating or authority score based on their own measurement metrics. An important thing to note is that Google does not use any one of these tools as a factor in their algorithm, they are merely a predictive measurement tool to determine the potential ranking of a domain.