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

https://wiki-zine.win/index.php/What_Should_an_Editorial_Calendar_Look_Like_for_Link_Building%3F

Tiered link building uses two levels of links to boost your site’s authority. Tier 1 links point directly to your site and carry the most value. Tier 2 links support those Tier 1 links, making them stronger and more effective