What are backlinks?
Backlinks are links from other websites to yours. Google uses links to find pages and as one signal of how relevant and trustworthy a page is, and links bought or traded to manipulate rankings break its spam policies.
Cited from the66th.com/glossary/backlinks
How backlinks work
A backlink is an ordinary link on someone else's page that points to a page on your site. Google follows it to discover your page, and reads its anchor text, the clickable words of the link, as a description of what your page covers.
The site giving the link can label it with a rel attribute, a short tag inside the link's code. rel="sponsored" marks a paid link, rel="ugc" marks a link a user posted in a comment or forum, and rel="nofollow" marks a link the site would rather Google not associate with it. The table shows how the same kind of link can fall on either side of Google's rules.
| The link | How it is marked | Within Google's rules? |
|---|---|---|
| A local news story on frozen pipes that quotes the plumber and links to its site | Ordinary link | Yes. The publication chose to give it. |
| A paid sponsor mention on a community blog | rel="sponsored" | Yes. The paid link is labeled. |
| A paid article on another site with the link text "best plumber Calgary" | Ordinary link | No. Google lists this as link spam. |
| Hundreds of low-quality directory listings | Ordinary link | No. Google lists these as link spam. |
Why Google cares about backlinks
Google's link best practices say Google uses links as a signal when it judges how relevant a page is, and to find new pages to crawl. Google's own explanation of how it ranks results says one factor in judging quality is whether other prominent websites link to or refer to the content.
Google's link spam policy sets the limits. Buying or selling links for ranking, excessive link exchanges, automated link building, and paid articles or guest posts with keyword-rich links all count as link spam. A paid link is allowed when it carries rel="sponsored" or rel="nofollow".
What it means for your business
Backlinks matter when your page already answers the search and competitors with similar pages rank above you. Relevance counts: a link from a Calgary news site or a trade association reaches a plumber's buyers, while a link from an unrelated blog in another country reaches no one who will call.
A business with a handful of thin pages gets more from building those pages first, because a link needs a page worth reading at the other end. Earning links is one part of our SEO services, alongside the pages and technical fixes the links point to.
Common mistakes
- Buying links that pass ranking credit. It is the first example in Google's link spam policy; label any paid placement as sponsored.
- Judging links by the total count. Low-quality directory and bookmark links are on Google's link spam list, so a long list of them adds risk instead of value.
- Asking every site for the same keyword-rich link text. Google names optimized anchor text in guest posts and press releases as link spam; let the linking site describe you in its own words.
Related terms
Sources: Google Search Central, Link best practices for Google, 10 December 2025; Google Search Central, Spam policies for Google web search: link spam, 28 August 2026; Google, How Search works: ranking results.