Tiered link building helps you boost your website’s authority by building links...

https://list-wiki.win/index.php/Guest_Posting_for_Tier_1_Links_-_What_Should_I_Watch_Out_For%3F

Tiered link building helps you boost your website’s authority by building links in layers. Tier 1 links point directly to your site and carry the most value. Tier 2 links support those Tier 1 links, making them stronger and more effective