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

https://www.echobookmarks.win/tiered-link-building-scales-site-authority-use-ahrefs-to-map-tier-1-links-and

Tiered link building uses two levels of backlinks to boost your site’s authority. Tier 1 links point directly to your site, while Tier 2 links support those Tier 1 backlinks