Domain Authority is a third-party score, most commonly on a scale of 1 to 100, that estimates how likely a website is to rank in search results based largely on the quantity and quality of sites linking to it. It is an industry estimate, not a metric Google publishes.
It gives a rough sense of competitive standing. Comparing your score to local competitors tells you whether you are playing on roughly even ground or starting well behind.
It is a guide, not a target. Google does not use Domain Authority, so chasing the number for its own sake is a mistake. It is useful for comparison, not as a goal.
For a small business, the inputs matter more than the score. The score rises as a natural result of earning good backlinks and publishing useful content, so focus on those and the number follows.
A new law firm has a Domain Authority of 8. The two established firms it competes with locally sit around 30.
That gap explains why the new firm struggles to rank for competitive terms straight away, and it sets a realistic expectation: closing it takes consistent work, not a quick fix.
Rather than obsessing over moving the number from 8 to 9, the firm focuses on the things that cause it to rise, useful content and genuine local links, and treats the score purely as a progress check.
In-House tracks authority signals through the SEO agent as one input among many, and focuses the work on the content and links that actually move rankings.