Domain Authority (capital letters) is actually Moz's proprietary score; Ahrefs calls its version Domain Rating. Neither is a Google metric — they are educated guesses at the thing Google does measure: the aggregate strength of a domain's link profile and track record. The useful intuition they capture is real, though: a strong domain lifts every page on it, which is why a new page on an established site can outrank better content on a new domain.
The practical use is directional, not precise: track the trend rather than the number, and treat it as a proxy for 'how much does the web already trust us'. Building it is building links and history — there is no shortcut, which is why an old, well-cited domain is itself an asset worth not throwing away in a rebrand.
Related terms
Backlink
A link from another site to yours — still the strongest external ranking signal, valued by quality and relevance, not count.
Topical authority
Being the site that covers a subject completely — many well-linked pages on one topic beat one page on many topics.
Organic traffic
Visitors who arrive from unpaid search results — the compounding channel that keeps working after the work is done.
SEO
Search engine optimization — making pages findable, indexable and worth ranking: technical health plus content people actually want.
The bench this belongs to
Web performanceA rebuild that loads on a phone on mobile data, in the country your customers are actually in. Core Web Vitals are the measurement, revenue is the point.
