Every field hides behind its vocabulary, and SEO is worse than most. This glossary defines the backlink terms you'll actually meet, each in one plain sentence, with a link to the full guide where there's more worth knowing. Skim it once and the rest of the internet's link advice gets a lot easier to read.
Core terms
Backlink
A link on another website that points to yours. It is the core unit of off-page SEO. See how to find your competitors' backlinks for what to do with them.
Referring domain
A unique website that links to you. Ten links from one site count as one referring domain, which is why referring domains are a more honest measure than raw link count.
Inbound link (backlink)
Another name for a backlink, meaning a link coming into your site. "Inbound link analysis" just means reviewing those links; see how to check who is linking to your website.
Outbound link
A link from your site to another. The mirror image of a backlink.
Anchor text
The visible, clickable words of a link. Anchor text gives search engines a hint about the linked page's topic. Natural, varied anchors look healthy; dozens of identical exact-match commercial anchors look manipulated.
Quality signals
Domain Rating (DR)
A 0–100 score estimating a site's authority from its backlink profile. It's a third-party metric, not a Google ranking factor. Treat it as a useful rough sort order, and don't treat it as gospel.
Domain Authority (DA)
Moz's equivalent of DR: same idea, different provider and scale. Compare like-for-like; don't mix DA and DR as if they're the same number.
Dofollow link
The default link type, which passes authority ("link equity") to the target. It's the link that most directly helps rankings. See the full explanation in dofollow vs nofollow.
Nofollow link
A link marked so search engines don't pass standard authority. It's still valuable for traffic and discovery, and Google now treats it as a hint, not a hard rule.
rel="sponsored" marks paid or affiliate links; rel="ugc" marks user-generated content like comments. Both signal a link shouldn't pass normal ranking authority.
Link equity
The ranking value ("authority") a link passes from one page to another. Sometimes called "link juice." Dofollow links pass it; nofollow links largely don't.
Toxic backlink
A link from a spammy or manipulative source that can harm rankings. It's rarer and less dangerous than tools imply, so see finding and removing toxic backlinks before you panic.
Link building
The practice of earning backlinks to your site. The honest version is covered in where to get backlinks that actually count.
Link gap analysis
Comparing several competitors' profiles to find domains that link to them but not you. These are your highest-probability link targets. Part of analyzing a competitor's backlink profile.
Broken link building
Finding a dead link on someone's page and offering your working resource as the replacement. It's one of the highest-conversion outreach tactics. See replicating competitor backlinks.
Disavow
Telling Google to ignore specific links via its Disavow Tool. A last resort, not routine maintenance.
PBN (private blog network)
A network of sites built solely to sell or place links. It's a manipulative pattern and a penalty risk, not a shortcut.
Backlink checker
A tool that returns the backlinks pointing at any domain. Compare the options in best competitor backlink tools.
Put the vocabulary to work
See how we map a domain's referring links in clear terms. Run a free scan on any competitor, no account needed.
Bookmark this page and the rest of the site's guides will read faster, because every term above links to the place where it actually matters.
