Dark data is all the information your team stores but rarely uses—up to 80% of...

https://wiki-nest.win/index.php/Does_Dark_Data_Affect_Backup_and_Disaster_Recovery_Costs%3F

Dark data is all the information your team stores but rarely uses—up to 80% of it can sit inactive. This hidden data drives up storage costs, creates security risks, and clutters AI projects with useless noise