Dark data is all the information stored but never used—think of files taking up...

https://kilo-wiki.win/index.php/Can_I_Tier_Inactive_Data_Without_Breaking_User_Access%3F

Dark data is all the information stored but never used—think of files taking up space but adding no value. Around 55% of enterprise data falls into this category, which leads to wasted storage costs and higher security risks