Dark data is the information your company stores but never uses—think 55% of...

https://iris-wiki.win/index.php/How_Do_I_Find_Log_Files_That_Are_Eating_Up_Storage%3F

Dark data is the information your company stores but never uses—think 55% of your files just sitting there. It matters because keeping that unused data racks up storage costs and risks, like data breaches