Definition
A link is a clickable connection between two pages, either within the same site (an internal link) or pointing to a different site (an external link). Search engines follow links to discover new pages, and they also use the pattern of links pointing to a page as one signal of how useful or trustworthy that page is.
User Cases
A blog post links to a related article on the same site, helping readers find more information and helping search engines understand how the two pages relate. A news site earns a link from a university’s website after being cited as a source, which strengthens the news site’s authority on that topic. An online store links its category pages to individual product pages, giving search engines a clear path to every item in the catalog. In each case, the link is doing two jobs at once: guiding a reader and guiding a crawler.
Why It Matters for SEO
Links remain one of the strongest ranking signals in search. A page that earns links from many relevant, trustworthy sites is treated as more credible, a concept known as link equity. The text used in a link, called anchor text, also helps search engines understand what the linked page is about. The practice of earning links intentionally, known as link building, remains one of the core disciplines in SEO.
Related Concepts
Related concepts include the backlink, which is simply a link pointing to a site from somewhere else on the web, and the overall network of links across the internet, which search engines use to map relationships between pages and sites.