What Are Backlinks? The Complete Guide to Link Building in 2026

If you have ever wondered what are backlinks and why every SEO professional obsesses over them, this guide covers everything from the basics to advanced link building strategies that move rankings in 2026.

Every SEO conversation eventually comes back to one topic: backlinks. Whether you are a business owner trying to grow organic traffic, a marketer launching a new website, or an SEO professional managing multiple clients, backlinks sit at the core of every successful search engine optimisation strategy.

But what are backlinks, exactly? Why does Google care about them so much? And how do you actually build them in a way that moves rankings? This guide answers all of that, step by step, with no fluff.

What Are Backlinks?

So, what are backlinks in simple terms? A backlink is a hyperlink on one website that points to a page on another website. When Site A links to Site B, Site B receives a backlink. From Site B’s perspective, that link is an inbound link. From Site A’s perspective, it is an outbound link.

Search engines like Google treat backlinks as votes of confidence. When a high-authority website links to your content, it is essentially telling Google: “This page is worth reading.” The more credible votes you accumulate, the more Google trusts your site and the higher it tends to rank your pages in search results.

Think of backlinks like citations in academic research. The more reputable journals cite your paper, the more credible your research appears. Google works the same way with websites. Just as researchers ask what are backlinks between papers when measuring academic influence, Google measures the links between websites to determine authority and trust.

Understanding what are backlinks also means understanding their direction. Every backlink you receive is a signal from another website vouching for your content, and every backlink you give is your site vouching for someone else. That exchange of trust is the foundation of how Google ranks the entire web. At their core, what are backlinks if not the internet’s way of saying this page deserves to be found.

How Backlinks Work in SEO

Now that you understand what are backlinks at a basic level, it helps to understand the mechanism behind them. When Googlebot crawls the web, it follows links. Every time it encounters a link pointing to your page, it records that connection and factors it into how it evaluates your site’s authority and relevance.

The mechanism behind what are backlinks works on two levels.

The first is authority transfer, sometimes called link equity. Each page on the internet holds a certain amount of authority. When a page links to yours, it passes a portion of that authority to your page. A single backlink from a high-authority news site like the BBC or Forbes can carry more weight than a hundred links from low-quality blogs.

The second is discovery and indexing. To fully grasp what are backlinks and their power, consider how they help Google discover your pages faster. If Googlebot finds a link pointing to a new page on your site from a page it regularly crawls, it will follow that link and index your content more quickly than if it had to find the page on its own.

Types of Backlinks

Understanding what are backlinks also means understanding that not all of them are equal. Google recognises several different types, and each one has a different impact on your rankings.

• Dofollow backlinks are the standard type. They pass authority from the linking page to yours. Most editorial links you earn naturally are dofollow by default. These are the links that directly improve your rankings.
• Nofollow backlinks contain a rel=”nofollow” attribute in the HTML. Originally, Google said these links passed no authority at all. In 2019, Google updated its stance and now treats nofollow as a hint rather than a directive, meaning it may choose to follow and credit some nofollow links. While they carry less direct ranking power, they still drive referral traffic and help diversify your link profile.
• Sponsored backlinks must be tagged with rel=”sponsored” when you pay for a link placement. This signals to Google that the link is commercial rather than editorial. Failing to do this is a violation of Google’s webmaster guidelines and can lead to manual penalties.
• UGC backlinks come from user-generated content such as blog comments, forum threads, or community platforms. These carry the rel=”ugc” attribute and are the lowest-value backlinks. They should not be a primary focus of any link building strategy.
• Editorial backlinks are the gold standard. These are links that other websites give you naturally because they find your content valuable, cite you as a source, or reference your research. You cannot buy or request these links. You earn them by producing exceptional content.

What Makes a Backlink High Quality?

When people ask what are backlinks worth, the answer depends entirely on quality. Google evaluates each backlink across several dimensions.

1. Domain authority of the linking site carries significantly more weight than a link from a brand new blog with no followers. A link from a high-authority website passes far more value to your page. Tools like Ahrefs Domain Rating and Moz Domain Authority give you a proxy score for this. When evaluating what are backlinks worth, domain authority is always the first metric to check.
2. Relevance is a signal Google values heavily. A backlink from a marketing blog linking to your SEO agency is far more valuable than a link from a food recipe site linking to the same page. The more relevant the linking page’s topic is to yours, the stronger the signal.
3. Anchor text is the clickable text that contains the hyperlink. Google reads anchor text to understand what your page is about. If a site links to you using the anchor text “best SEO agency in London,” that sends a strong relevance signal for that keyword phrase. However, an unnatural concentration of exact-match anchor texts is a red flag that can trigger Google’s Penguin algorithm.
4. Placement on the page determines how much weight the link carries. A link placed within the main body content of an article is worth far more than one buried in a footer or sidebar. Google’s algorithms understand the difference and apply different weighting accordingly.
5. Link uniqueness matters because getting your second link from the same domain delivers diminishing returns compared to your first. Building links from a wide range of unique domains is more valuable than accumulating multiple links from the same site. This is a critical factor in understanding what are backlinks and why diversity across referring domains matters more than volume from a single source.

One backlink from a DR 80 website in your industry is worth more than 50 backlinks from spammy directories. Always prioritise quality when asking what are backlinks.

How to Build Backlinks: 8 Proven Strategies

Knowing what are backlinks is only half the battle. The real work lies in building them.

• Guest posting involves writing high-value articles for authoritative blogs in your niche and including a contextual link back to a relevant page on your site. Focus on websites with genuine audiences, not link farms.
• Digital PR and link bait means creating original research, data studies, or opinion pieces that journalists and bloggers are compelled to cite. A single well-placed piece of research can earn hundreds of backlinks.
• Broken link building involves finding broken links on high-authority websites in your niche, reaching out to the webmaster to notify them, and suggesting your content as a replacement.
• Resource page link building targets websites that maintain “resources” or “useful links” pages. You identify these pages in your industry and pitch your content as a worthy addition.
• The Skyscraper Technique means identifying the best-ranking content for your target keywords, creating a dramatically better version, and then reaching out to everyone linking to the original to show them your superior resource.
• HARO and journalist outreach involves signing up to Help a Reporter Out and similar platforms. When you respond to journalists seeking expert quotes and they publish, they typically link back to your website as the source.
• Unlinked brand mention monitoring means tracking the web for mentions of your brand name without a link. When someone mentions you without linking, reach out and ask them to add it. These are often the easiest backlinks to earn.
• Competitor backlink replication involves using tools like Ahrefs or SEMrush to analyse your competitors’ backlink profiles, identify the sites linking to them, and build relationships to earn those same links for your site.

Backlinks vs Internal Links

A common question from those learning what are backlinks is how they differ from internal links. Backlinks come from external websites. Internal links connect pages within the same website. Both matter for SEO but serve different purposes.

Internal links help Google understand the structure of your website and distribute authority across your pages. Backlinks bring external authority into your site from the wider web. A strong SEO strategy uses both: internal linking to spread the power of earned backlinks across your entire site, and external link building to continuously grow that pool of authority.

When you earn a strong backlink to one page, use internal links from that page to other important pages on your site. This distributes the authority you have earned and lifts your wider rankings.

The difference between what are backlinks and what are internal links comes down to source: one is external, one is internal, but both work together to build your site’s overall SEO strength.

Common Backlink Mistakes to Avoid

Building backlinks incorrectly can do more harm than good.

1. Buying links from link farms is the most dangerous mistake. Google’s Penguin algorithm is specifically designed to detect and penalise paid link schemes. The short-term ranking boost is never worth the long-term penalty risk.
2. Over-optimising anchor text makes your link profile look unnatural. If every backlink to your page uses the exact same keyword as anchor text, Google flags it immediately. Vary your anchor text across branded, generic, and partial-match terms.
3. Ignoring link relevance dilutes the topical authority signal you are trying to build. Prioritise links from within your niche rather than completely unrelated industries.
4. Neglecting nofollow links leaves your link profile looking suspicious. A natural backlink profile contains a mix of dofollow and nofollow links. A profile with zero nofollow links is a red flag.
5. Building links to weak pages scatters your efforts and wastes the authority you earn. Focus your link building on your most important pages: your homepage, service pages, and cornerstone content.
6. Chasing quantity over quality is perhaps the most common mistake of all. One link from an authoritative, relevant source beats a hundred links from low-quality directories. Always think quality first.

Conclusion

Backlinks remain one of the most reliable and enduring signals in SEO, and understanding what are backlinks is the first step toward building a strategy that actually compounds over time.

From dofollow links that pass direct authority to editorial mentions that cement your credibility, every backlink you earn is a vote that tells Google your content deserves to be found. The brands that win in search are not the ones publishing the most content.

They are the ones building the most trust, and trust in SEO is measured in links. Start with quality, stay consistent, track your profile regularly, and treat link building as a long-term asset rather than a quick fix.

The results will follow.