Dark data is the information companies collect but never use. It often makes up...

https://wiki-spirit.win/index.php/Can_I_Really_Tag_Petabytes_of_Files_with_Custom_Python_Metadata%3F

Dark data is the information companies collect but never use. It often makes up 60-80% of stored data, quietly taking up space and costing businesses millions—sometimes $2.5 million annually