SEO & performance
Internal linking
Internal linking is how pages on a site link to each other. It tells search engines which pages relate and which matter, and gives visitors somewhere to go next instead of leaving.
A site whose articles link only to the homepage and the contact page is a set of islands. Search engines cannot tell that ten articles about the same subject form a cluster, and readers who finish one have nowhere to continue except the exit. Linking related pages to each other fixes both, at no cost beyond deciding what relates to what.
Two properties matter. Every page should be reachable from at least one other page in the body content, not only from the navigation, because navigation links carry less meaning. And the distribution should be deliberate: a page that receives links from many others reads as important, and that should be the page you want to rank.
It is the cheapest SEO lever a site has, entirely under its owner's control, and the one most often left undone. An audit that finds forty orphan articles has found the fastest win on the list.
Internal links in the SEO checklistSEO & performance