A backlink is a link on one website that points to another website. If Site A links to Site B, then Site B has earned a backlink. That's the whole definition — but in SEO, those links are one of the strongest signals Google uses to decide which pages rank.
A backlink in one sentence
When another site includes a clickable link to your page, you've got a backlink (also called an "inbound link"). Google treats each one a bit like a vote: a page that lots of trustworthy sites link to is probably worth showing near the top of search results.
A real backlink example
Say you run a coffee blog and a well-known food magazine publishes an article that says:
For a deeper dive, see this guide to pour-over ratios.
That linked phrase — "guide to pour-over ratios" — pointing to your blog is a backlink. Break it into its parts:
- Linking page: the magazine's article (the source of the vote)
- Anchor text: "guide to pour-over ratios" — the clickable words. If you want to understand why these words matter, see what is anchor text.
- Destination: your blog post (the page getting the credit)
Why backlinks matter for SEO
Google's original breakthrough was treating links as endorsements. The logic still holds: it's hard to fake dozens of real websites choosing to link to you, so links are a trust signal that's expensive to game. Pages with strong, relevant backlinks tend to:
- Rank higher for competitive keywords
- Get discovered and crawled faster
- Pass "authority" that lifts other pages on the same domain
This is closely tied to domain authority — a score that estimates how much link-based trust a whole site has built up.
Not all backlinks are equal
A backlink from a respected, on-topic site is worth far more than one from a spammy directory. The factors that separate a strong link from a weak one:
- Relevance — a link from a site in your niche counts more than a random one.
- Authority — a link from a trusted domain carries more weight.
- Placement — a link inside real article content beats one buried in a footer.
- Dofollow vs nofollow — whether the link passes ranking signals at all. See dofollow vs nofollow links.
Link vs. backlink — what's the difference?
People mix these up. A link is any clickable connection between two pages. A backlink is specifically an incoming link from another website to yours. Every backlink is a link, but a link from your homepage to your own pricing page is an internal link, not a backlink.
How do you actually get backlinks?
You earn them by publishing things worth linking to, or you build them deliberately — guest posts, digital PR, directories, and link exchanges where two site owners agree to link to each other. Backlinkster is built for that last one: it matches you with real site owners to swap in-content links, and verifies each link is actually live by API. The upside of a swap is you skip the wait for organic links; the risk is doing it carelessly, which is why every link should sit in genuine content.
The bottom line
A backlink is simply another site vouching for yours with a link — and after 25+ years of Google, it's still one of the few ranking signals that's genuinely hard to fake. Understanding what makes one good is where most of the SEO value lives.
Related: How do backlinks work? · Are backlinks good for SEO? · Link Building vs Backlinks: What's the Difference? · What are internal links in SEO? · What is link building?