What Is a Backlink (and Link Equity)?
Short answer
A backlink is a link from another website to yours, and link equity is the authority it passes. Backlinks remain one of the oldest ranking signals in search, and in AI search they take on a second role: corroborating that what your site claims is confirmed elsewhere.
Backlink / Link Equity explained
Backlinks have anchored search ranking since Google's founding insight that links function as votes: a page linked by many trusted pages is probably trustworthy itself. Link equity is the portion of that authority a link passes to its destination, shaped by the linking site's own authority, the link's placement, and its anchor text.
Quality beats quantity, and it isn't close. A handful of links from respected, topically relevant sites outweighs hundreds of low-grade directory entries, and manipulative patterns invite trouble: Google's Penguin update in 2012 began actively penalizing unnatural link profiles, and reciprocal link schemes were discounted years before that. Ahrefs' analysis of roughly 14 billion pages found that of about 20 million pages with no referring domains, only 2,997 draw more than 1,000 monthly search visits, roughly 1 in 6,671, which is both the challenge and the opportunity: earning even a modest number of genuine links puts a page ahead of most of the web.
In AI search, backlinks and the mentions that accompany them serve corroboration. LLMs favor information that appears consistently across independent sources, so a link is no longer just an authority vote; it's evidence that a third party repeats and confirms your story. That shift also changes outreach priorities: unlinked brand mentions in credible places now carry real weight, because a model reads the mention even where a crawler finds no link.
In practice
The reframe I give clients: LLMs want to corroborate. They want the information on your website to exist elsewhere on the web, consistently. So I treat backlinks and brand mentions as corroboration infrastructure now, on top of authority points. The question is no longer only how strong the linking domain is, but whether the coverage around the link tells the same story your site tells. Inconsistency between your site and your citations is a visibility problem most link builders never look for.
Common misconception
People often believe any inbound link helps, or panic that any bad link hurts. Most low-quality links are simply ignored, genuine editorial links compound, and it takes manipulation at scale to earn a penalty.
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