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

https://www.yankee-bookmarkings.win/tiered-link-building-helps-boost-your-website-s-seo-by-building-strong

Tiered link building uses two levels of links to boost your website’s rankings. Tier 1 links point directly to your site and should be high quality. Tier 2 links support those Tier 1 links, helping them rank better in search results