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

https://wakelet.com/wake/gzbNnURt3wxkjVZmBBxos

Tiered link building uses two levels of backlinks to boost your site’s ranking. Tier 1 links point directly to your site and are high quality. Tier 2 links support those Tier 1 links, helping them gain strength and improve their value