Backlink

A backlink is a hyperlink on one website pointing to a page on another. Search engines treat backlinks as a signal of authority and relevance: a link from an established, topically related site is generally read as a vote of confidence in the linked page, though not all links are treated equally or even counted.

A backlink's value depends heavily on quality signals — the linking domain's own domain authority and topical relevance, where on the page the link sits, the anchor text used, and whether the link is marked "nofollow," historically a signal search engines wouldn't pass ranking credit through, though Google now treats it as a hint rather than a strict rule. This differs from referral traffic, which measures actual clicks on a link; a backlink can carry SEO value even if almost no one ever clicks it.

Backlinks remain one of Google's confirmed major ranking inputs and are core to how organic traffic and search engine results page rankings are built over time. The best-known pitfall, going back to early search-optimization practice, is treating link volume as inherently good: acquiring large numbers of low-quality, irrelevant, or purchased links can trigger manual penalties or algorithmic devaluation rather than improving rankings, since search engines actively model and discount manipulative link patterns.