Backlinks Explained
What counts as a backlink, the four types you'll actually encounter, and why relevance beats volume every time.
Every link-building tactic exists to earn one thing: a backlink.
So it's worth being precise about what one actually is, what makes one valuable, and what the different types mean in practice — before getting into the tactics that earn them.
This is one entry in our link building guide. For the tactics themselves, see what still works in India in 2026.
What is a backlink?
A backlink — also called an inbound link or an incoming link — is a hyperlink on one website that points to a page on a different website. If a health blog links to a page on your clinic's site, that's a backlink to you.
Search engines have used links as a ranking signal since the earliest days of PageRank, on the logic that a link is a small act of endorsement: someone found your page worth pointing their own readers to. That logic still holds, with one major caveat — not all endorsements are equal.
What makes a backlink valuable
Four things decide how much a given backlink is actually worth to you.
| Factor | Why it matters |
|---|---|
| Relevance | A link from a site in your field or adjacent to it carries more weight than a link from an unrelated industry |
| Authority of the linking domain | A trusted, established site passes more credibility than a brand-new or low-quality one |
| Placement and context | A link inside the body of an article, surrounded by relevant text, outperforms a link buried in a footer or sidebar |
| Link attribute | Whether the link is dofollow, nofollow, sponsored or UGC changes what it's intended to pass — see below |
The four types of backlink
Every link carries an attribute — explicit or implied — that signals its intent. Google introduced three of these formally in 2019 to give site owners a way to be honest about link type without being penalised for it.
- Dofollow. The default. No extra attribute is present, and the link is intended to pass ranking credit to the destination.
- Nofollow (
rel="nofollow"). Originally told search engines not to pass any credit at all. Since March 2019, Google treats it as a hint rather than a strict rule — it can still choose to consider the link in some contexts. - Sponsored (
rel="sponsored"). Marks a paid or advertising link. Using it correctly is what separates a disclosed, legitimate paid placement from a manipulative link scheme. - UGC (
rel="ugc"). Marks a link inside user-generated content — a forum reply, a blog comment, a review. It tells search engines the site owner didn't personally vouch for the link.
A healthy backlink profile usually contains a mix of all four. A profile made up entirely of dofollow links from anonymous or low-quality sources is itself a red flag — see toxic links for what that risks.
How backlinks are actually earned
There are three broad routes to a new backlink, and they are not equally sustainable.
- Earned. Someone links to you unprompted because your content, data or product genuinely deserved it. The most durable route, and the hardest to manufacture on demand — digital PR is built specifically to earn this kind of coverage.
- Built. You actively request or place the link — writing for another site, fixing a broken link with your own resource, or reaching out to someone already covering the topic. See guest posting and broken link building.
- Bought. A link placed in exchange for payment, intended to pass ranking credit without disclosure. This violates Google's guidelines and is the route we don't take on behalf of clients — see the risk in full under toxic links.
What a backlink is not
A few things get confused with backlinks that aren't the same thing:
- A brand mention without a link is not a backlink, though Google's algorithms are widely understood to weigh unlinked mentions to some degree as a trust signal.
- An internal link — one page on your own site linking to another — is a separate discipline. See internal linking.
- The words used in the link itself are the anchor text, which is its own factor with its own risks. See anchor text.
Where to go next
Domain authority is the metric backlinks are usually built to move. Guest posting and digital PR are the two most durable ways to earn them. And toxic links covers what happens when the route to a backlink was the wrong one.
Frequently asked questions
What is a backlink in simple terms?
A backlink is a link on someone else's website that points to yours. Search engines treat it as a signal that another site considers your page worth pointing readers to, and it remains one of the strongest ranking signals — provided the linking site itself is relevant and trustworthy.
What is the difference between dofollow and nofollow backlinks?
A dofollow link is the default — no extra attribute — and is intended to pass ranking credit. A nofollow link carries rel="nofollow" and originally told search engines not to pass credit at all. Since 2019, Google treats nofollow as a hint rather than a strict instruction, and can still choose to consider it. Either type can send real referral traffic and build brand awareness.
What are sponsored and UGC links?
Both are attribute values Google introduced in 2019 alongside nofollow. rel="sponsored" marks a paid or advertising link, and rel="ugc" marks a link inside user-generated content such as a forum post or comment. Using the correct attribute is what keeps a legitimate paid placement or open comment section from looking like a manipulative link scheme.
Do more backlinks always mean better rankings?
No. A handful of links from relevant, trusted sites in your field outperforms hundreds of links from unrelated or low-quality domains. Relevance and the linking site's own trust matter more than raw count, which is exactly why link-building tactics built around volume — directories, link farms, bulk guest-post networks — tend to underperform or backfire.
How do I check who links to my site?
Google Search Console's Links report is free and shows the domains linking to your site, though it is not exhaustive. Paid tools such as Ahrefs, Semrush and Moz crawl the wider web and give a fuller, though still incomplete, picture — no single tool sees every link that exists.
Not sure what your backlink profile actually looks like?
Send us the domain. We'll tell you what's helping, what's doing nothing, and what's worth disavowing.