Dark data is the inactive or unused information sitting in your systems—often...

https://remote-wiki.win/index.php/How_Do_I_Report_on_File_Age,_Owner,_and_Last_Access%3F

Dark data is the inactive or unused information sitting in your systems—often 60% to 80% of it. It quietly drains budgets, wastes about $2.5 million annually for some firms, and adds noise that confuses AI projects