Internal links are links that go from one page on a domain to a different page on the same domain. They are commonly used in main navigation.
These type of links are useful for three reasons:
- They allow users to navigate a website.
- They help establish information hierarchy for the given website.
- They help spread link equity (ranking power) around websites.
The search engines don’t rank websites as a whole in the SERPs – they rank individual pages. For most websites, the homepage is going to get most of the traffic and inbound links, but that doesn’t mean that deeper internal pages can’t also be useful from an SEO standpoint. However, in order for those internal pages to effectively compete in the search results they need their own (albeit smaller) link portfolio and search engine trust.
That’s where internal linking comes into play – but there’s a right way and a wrong way to do it. You don’t need to have every link on every page of your site.