Dark data is the hidden, unused information companies store without realizing...

https://wiki-neon.win/index.php/Dark_Data_and_AI_Governance:_What_Should_Be_Blocked_from_Ingestion%3F

Dark data is the hidden, unused information companies store without realizing the cost and risk it brings. For example, up to 80% of stored data can be inactive, taking up space and driving up expenses