An internal link is any link from one page on a website to another page on that website. Both your visitors and Google use links to find content on your website. Google follows links to find content on websites and to rank this content in the search results. If a post or page gets a lot of links this is an indication to Google that it’s valuable or high-value content. This counts for both internal links and external links.
Internal linking is a thing that you control as a site owner. With the correct internal links, you’ll guide your users and search engines to your most important pages.
Google crawls websites by following links, both internal as well as external, using a bot called Googlebot. This bot enters the homepage of a website, starts to render the content, and follows the first link. By following links Google can work out the relation between the different pages, posts, and other content. This way Google finds out which pages on your website cover a similar subject matter.
Link value
In addition to understanding the relationship between content, Google distributes link value between all links on a web page. Mostly, the homepage of any website has the maximum link value because most of the backlinks are there. That link value will be shared between all the links found on that homepage. The link value passed to the following page will be divided between the links on that page, and so on.
Therefore, the newest blog posts will get more link value if people link to them from the homepage, instead of only on the category page. And Google can find new posts easier if they’re linked from the homepage.
When you understand the concept that links pass their link value on, you’ll get that more links to a post mean more value. Because Google considers a page that gets lots of valuable links as more important, it will increase the chance of that page ranking.