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

https://mighty-wiki.win/index.php/Why_Do_Some_Sites_Reject_Outreach_Even_When_My_Content_Is_Good%3F

Tiered link building uses two levels of backlinks to boost your site's authority. Tier 1 links point directly to your site and carry the most value. Tier 2 links support those Tier 1 pages, helping increase their strength and improve your rankings