A backlink is a hyperlink on one website that points to a page on another website. This page defines backlinks for SEO, shows the parts of a link that search engines read, compares nine backlink types, and separates backlinks from referring domains. It is the starting point for the Backlink Agency guides on link quality, link attributes, indexing and link profiles.
What is a backlink?
A backlink is a hyperlink on one website that points to a page on another website. The linking site is the source, the page receiving the link is the target, and the target page gains one inbound link, also called an incoming link, from that source.
A hyperlink is a clickable reference that moves a reader or a crawler from one URL to another. Every backlink is a hyperlink, and every hyperlink is a backlink for the page it points to. The term describes the link from the target’s side: a site with 120 backlinks has 120 hyperlinks on other pages that point at it.
What are backlinks in SEO?
Backlinks in SEO are links from other websites that search engines use to discover pages and to judge their reference value. Google’s PageRank method, described in 1998, treats each link as a reference. Links are one ranking signal among many.
PageRank is the link-analysis method Larry Page and Sergey Brin described in 1998 while at Stanford University. It models a link as a citation: a page that many credible pages cite earns more reference value than a page nobody cites. Search engines also follow links to find new URLs, which makes backlinks both a discovery path and a quality signal.
Backlinks fall into two groups. Earned links come from site owners who cite a page without a request. Placed links come from outreach, contributed articles and paid placements. Both groups appear in the same link report, and Google’s spam policies govern the second group.
How does a backlink work?
A backlink works through an HTML anchor element whose href attribute holds the target URL. The element wraps the anchor text, and an optional rel attribute tells search engines how to treat the link. Crawlers follow the href from the source page to the target.
<a href="https://example.com/guide/" rel="nofollow">link building guide</a>- The href attribute holds the target URL, here
https://example.com/guide/. - The anchor text holds the clickable words, here “link building guide”.
- The rel attribute holds the link attribute, here
nofollow; a missing rel attribute means the link is a standard followed link. - The source page holds the element, and its topic, authority and indexation state shape the link’s value.
What types of backlinks exist?
Nine backlink types exist: editorial, guest post, niche edit, directory and citation, profile, forum and user-generated, Web 2.0, private blog network, and press release. They differ in who places the link, where it sits on the page and which rel attribute it carries.
| Type | Where the link sits | Who places it | Usual rel attribute |
|---|---|---|---|
| Editorial | Inside an article body | The host’s writer | None (followed) |
| Guest post | Inside a contributed article | The contributor | Set by host |
| Niche edit | Inside an existing, indexed article | The host, on request | Set by host |
| Directory and citation | A listing page | The listed business | Often nofollow |
| Profile | A member profile page | The account owner | Often nofollow |
| Forum and user-generated | A post or comment | A community member | Often ugc or nofollow |
| Web 2.0 | A post on a hosted blog property | The blog owner | Set by platform |
| Private blog network | A post or homepage on an aged domain | The network owner | None (followed) |
| Press release | A syndicated release page | The issuer | Often nofollow |
Four of the nine types, guest post, niche edit, Web 2.0 and private blog network, are placed links. The remaining five come from the structure of the web or from the link owner’s own account.
What is the difference between a backlink and a referring domain?
A backlink is one link; a referring domain is one website that links to you, counted once. A site that links to you 40 times adds 40 backlinks and 1 referring domain. Referring domains measure breadth, backlinks measure volume.
Take a profile with 40 backlinks from 4 websites: it has 4 referring domains and an average of 10 links per domain. A profile with 40 backlinks from 40 websites has 40 referring domains. The second profile shows wider reference, which is why audits report both counts.
Do all backlinks carry the same value?
No, backlinks differ in value by the relevance, authority, placement and attribute of the linking page. A link inside an indexed, topical article carries more reference value than a sitewide footer link on an unrelated domain. Value comes from the page, not from the count.
- Relevance: the linking page covers a topic close to the target’s topic.
- Authority: the linking site holds its own links from credible sources.
- Placement: the link sits inside body content, not in a footer or a sidebar.
- Attribute: the rel value tells search engines whether to count the link.
The anchor text adds a fifth factor. A profile built from varied, descriptive anchors reads as natural, and the guide to a natural anchor mix sets out the ratios. Content that gives other sites something to cite, such as pages built through SEO Article Writing, produces the links that carry the most value.
How do you get backlinks?
Backlinks come from content worth citing, from contributed articles and from outreach to site owners. Each source differs in effort, cost and policy exposure, and the right one depends on the site’s age, budget and appetite for risk.
The full list of link acquisition tactics ranks each method by effort and policy exposure, and the page on common myths corrects the claims that lead site owners to the wrong method.
How do you see the backlinks pointing at your site?
Open the Links report in Google Search Console, or export referring domains from a backlink tool such as Ahrefs or Semrush. Search Console lists the sites and pages that link to you; third-party tools add authority metrics per source.
Search Console shows top linked pages, top linking sites and top linking text for a verified property, without showing whether a link carries nofollow. Third-party indexes show a larger set of links and add metrics such as Moz Domain Authority and Ahrefs Domain Rating.
A site owner who wants placed links in place of waiting for citations orders contextual guest placements, which put a one-way link inside a new article on a third-party site. Related guides on links, quality and risk sit in the backlink knowledge base.
Related: link packages with live reporting.