Dark data is the hidden information your company stores but rarely uses—often...

https://delta-wiki.win/index.php/Do_I_Need_to_Move_Petabytes_to_the_Cloud_to_Get_Value_from_Dark_Data%3F

Dark data is the hidden information your company stores but rarely uses—often making up 55% of all data. This idle data can cost millions, create legal risks, and clutter AI projects with irrelevant noise