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

https://mag-wiki.win/index.php/What_Should_I_Do_If_My_Tier_1_Backlink_Disappears%3F

Tiered link building uses two levels of links to boost your website’s SEO. Tier 1 links point directly to your site, giving it real authority. Tier 2 links support those Tier 1 links, making them stronger and more effective