Tiered link building uses two levels of backlinks to boost your site’s...

https://charlie-wiki.win/index.php/How_Do_Tier_1_vs_Tier_2_vs_Tier_3_Links_Actually_Work%3F

Tiered link building uses two levels of backlinks to boost your site’s authority. Tier 1 links point directly to your site from high-quality sources. Tier 2 links support those Tier 1 backlinks, helping them rank better and pass more value