What is a backlink?

Backlink, explained

When another site links to you, three things happen. Crawlers can find your page by following the link. People can click it and visit. And search engines can read the link as a kind of vote: someone else thought this page was worth pointing to. That third effect is why backlinks have been central to SEO since the early days of Google.

Not all backlinks are equal. A link from a relevant, well-read site in your field means more than one from an unrelated page. A followed link passes signals; a nofollow, ugc or sponsored link generally doesn't. And many links from one domain count for less than links from many different domains, which is why SEO tools report "referring domains" separately from total links.

Google also draws a clear line around how links are earned. Its spam policies define link spam as creating links to or from a site primarily to manipulate search rankings, and list examples: buying or selling links for ranking purposes, excessive link exchanges, and using automated programs or services to create links. Google's systems often just ignore those links, so the money and effort are wasted, and in worse cases there can be a manual action.

For a new product, the realistic backlink plan looks like this: get listed on relevant launch platforms and curated directories, which give your first links and brand mentions; publish things worth citing, like original data, free tools or clear guides; and show up where your users are. Links from customers, partners and integration pages come later and tend to be the strongest.

Backlinks also feed AI search indirectly. Assistants that search the web lean on pages that rank, and pages that rank tend to have earned links.

Why it matters for founders

A new domain with zero backlinks is slow to be crawled and hard to rank, no matter how good the content is. The first 20 to 50 relevant links are a foundation. They need to be earned in ways that won't be discounted later.

Example

A developer newsletter reviews your API tool and links to your docs. That single relevant, editorial link is worth more than a hundred links from generic directories with no readers.

Common mistakes

• Buying links or joining link exchange networks to grow faster.
• Counting total links instead of relevant referring domains.
• Ignoring nofollow links that send real users.
• Building links to the homepage only, never to the pages you want to rank.