What is a backlink
A backlink is a link on one website that points to a page on a different website.
Search engines treat it as a vote, because the linking site is sending its own readers to your page. That's the short answer to what is a backlink. It also explains why marketers track which sites link to them and why those links matter.
Exact definition for marketers
In marketing terms, a backlink is an inbound link from an external domain to your site. Search engines count it when they judge your site's authority. Links between your own pages are internal links, and they don't count as backlinks. The page that carries the link is the referring page, and the site it sits on is the referring domain. Track both numbers. Ten links from one site count for less than ten links from ten different sites.
What a backlink looks like
In the page's code, a backlink is an ordinary HTML anchor tag that points to your URL:
`<a href="https://example.com/composting-guide">beginner's guide to composting</a>`
The href holds the destination. The words between the tags are the anchor text, which tells readers and search engines what's on the other side. A link can also carry a rel attribute such as rel="nofollow" or rel="sponsored". These tell Google that the site doesn't vouch for the destination, or that someone paid for the link.
Why backlinks affect search ranking
Google uses backlinks as evidence that people find a page useful, so they affect where it ranks. PageRank, Google's original algorithm, scored each page by the number and quality of links pointing to it. Google's ranking systems have grown far more complex since then. But links still help Google find pages and decide which ones deserve to rank, so they're still relevant for SEO. A link won't lift a weak page above a better one, though, because Google weighs content and relevance alongside it.
How Google evaluates link authority
Google looks at more than how many links a page has. It also judges where each link comes from and why it exists. These are the three questions that matter most.
How strong is the referring page?
A link from a page that earns links from trusted sites passes on more value. Third-party scores like Moz Domain Authority estimate this strength, but Google doesn't use them. Treat them as rough guides.
Is the link relevant and placed in context?
A link from a site in your field counts for more than one from an unrelated site. Placement counts as well. When a link sits inside an article and the text around it explains why it's there, it reads as an editorial choice. A link in a footer reads like part of a template.
Why was the link created?
Google's link spam policy treats links built mainly to manipulate rankings as spam. That covers bought links and excessive link exchanges. Google ignores these links, and in serious cases it takes manual action against the site. If your rankings drop after a link campaign, check the Manual actions report in Google Search Console.
Backlinks in AI assistant citations
Backlinks affect AI assistant citations indirectly. Google's AI Overviews draw on pages in Google's index, and links already shape how that index ranks. Assistants that search the web, such as ChatGPT search, also pull from search results. Mentions of your brand on trusted sites, even without a link, help an assistant connect your name with a topic.
How to earn quality backlinks
You earn quality backlinks by publishing something other sites want to send their readers to. Then you make sure the right people see it.
Backlink quality vs quantity
One relevant link from a trusted site in your field can do more than hundreds of links from low-grade directories. A high-quality backlink comes from an authoritative page on your topic, and the site gave it freely. Quantity still counts because a steady rise in distinct referring domains looks natural. A sudden burst of links from unrelated sites looks like a scheme. Review your new links every month.
Related SEO terms
List your referring domains in Google Search Console and see which of your pages earn links.
Backlinks are one of the seven channels in off-page SEO for AI search, and Snoika's off-page SEO services earn them alongside reviews and community mentions.