Tiered link building boosts your site's authority by building links in layers....

https://www.stall-bookmarks.win/learn-how-tiered-link-building-boosts-your-site-s-authority-by-building-strong

Tiered link building boosts your site's authority by building links in layers. Start with Tier 1 links from trusted, relevant sites that point directly to your page. Then, support those with Tier 2 links that strengthen your Tier 1 sources