Backlink Explorer is powered by data from Majestic, which maintains two backlink databases: Fresh Index and Historic Index.
The Fresh Index is updated daily and contains data from the last 90 days. It generally has fewer links for a domain than the Historic Index, but links from the Fresh Index tend to have a higher probability of being live than those found in the Historic Index.
The Historic Index is updated less frequently but is Majestic's largest index of backlinks with data from the previous eight years. This data is updated roughly every four weeks and rarely overlaps with the Fresh Index.