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

https://www.phone-bookmarks.win/tiered-link-building-is-still-a-reliable-way-to-boost-site-authority-without

Tiered link building uses two levels of backlinks to boost your site’s ranking. Tier 1 links point directly to your site and carry the most weight. Tier 2 links support those Tier 1 links, helping them appear stronger to search engines