Dark data is all the information companies collect but never use, like old...

https://delta-wiki.win/index.php/How_Do_I_Set_Up_Governance_Controls_Before_AI_Ingestion%3F

Dark data is all the information companies collect but never use, like old files or unseen logs. It's huge—up to 80% of stored data can go untouched. That’s a big deal because managing this forgotten data can waste around $2.5 million each year