Dark data is the inactive or unused information companies store but don’t...

https://bravo-wiki.win/index.php/What_Are_Egress_Costs_and_Why_Do_They_Matter_for_Dark_Data%3F

Dark data is the inactive or unused information companies store but don’t analyze, making up about 60-80% of stored data. It wastes money on storage and backup and increases exposure to ransomware and data breaches