This article explains tiered link building, where Tier 1 links point directly...

https://fast-wiki.win/index.php/Can_I_Do_Tiered_Link_Building_Myself_or_Do_I_Need_an_Agency%3F

This article explains tiered link building, where Tier 1 links point directly to your site for strong SEO impact. Tier 2 links support those Tier 1 links, boosting their power and helping your rankings grow steadily