Referring Domain
In one line
Referring domains is the count of unique domains linking to your site — a more meaningful authority signal than raw backlink count, which can pile up from a single source.
Going deeper
Referring domains counts how many distinct sites link to you. One link from each of 100 sites is a much stronger signal than 100 links from a single site, which is why authority measurement leans on referring domains rather than raw backlink count.
Tools like Ahrefs, Majestic and Semrush put it front and centre for the same reason. Raw backlink counts can balloon from a single site's footer or sidebar link appearing on tens of thousands of pages, so normalising at the domain level is essential to avoid overcounting.
In day-to-day work it is more useful to track the referring-domain trend quarterly. Whether new domains keep arriving and whether the share of high-authority domains is rising tells you far more than any single snapshot number.
Related terms
Backlink
A backlink is an inbound link from another site to yours — one of the strongest signals search engines use to gauge a domain's authority and trustworthiness.
SEODA / Domain Rating
DA (Moz) and DR (Ahrefs) are third-party scores from 0 to 100 that estimate a domain's backlink authority — they are tool metrics, not Google scores.
SEOLink Building
Link building is the deliberate marketing, content and outreach work that earns inbound backlinks from other sites to yours.
SEOAnchor Text Diversity
Anchor text diversity is how naturally varied the anchor texts of your backlinks are — over-optimisation toward a single money keyword reads as a manipulative pattern to search engines.
SEOURL Rating (UR) / Page Authority (PA)
URL Rating (Ahrefs) and Page Authority (Moz) are vendor-specific 0-100 scores that estimate the link-equity strength of a single URL — they are page-level metrics from two different tools, not synonyms.
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