This article breaks down tiered link building, explaining how Tier 1 links...

https://highstylife.com/how-do-i-tell-if-a-backlink-is-relevant-or-just-high-da-fluff/

This article breaks down tiered link building, explaining how Tier 1 links point directly to your site to boost its authority. Tier 2 links then support those Tier 1 links, helping them rank higher