Dark data is the inactive or unused info lurking in your systems — often 60% to...

https://wiki-global.win/index.php/How_Do_I_Find_Dark_Data_on_a_NAS_Share%3F

Dark data is the inactive or unused info lurking in your systems — often 60% to 80% of it. It’s not just wasting storage and money but also creating risk and clutter that can confuse AI projects