Tiered link building uses two levels of links to boost your website’s...

https://super-wiki.win/index.php/Guest_Posting_for_Tier_1_Links_%E2%80%93_What_Should_I_Watch_Out_For%3F

Tiered link building uses two levels of links to boost your website’s authority. Tier 1 links point directly to your site from quality sources, while Tier 2 links support those Tier 1 links to make them stronger