Dark data is the vast amount of information companies store but never use—up to...

https://wiki-quicky.win/index.php/What_is_Transparent_Move_Technology_and_Does_It_Break_File_Access%3F

Dark data is the vast amount of information companies store but never use—up to 80% can sit inactive. It matters because this unused data costs businesses around $2.5 million every year in storage and management