Dark data is the info stored but never used, costing businesses millions and...

https://source-wiki.win/index.php/What_Should_I_Track_Monthly_to_Prevent_Dark_Data_from_Creeping_Back%3F

Dark data is the info stored but never used, costing businesses millions and cluttering systems. About 55% of data warehouses hold dark data, which can increase storage costs and create risks like compliance gaps