Dark data is the untapped information sitting in your files and systems that no...

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

Dark data is the untapped information sitting in your files and systems that no one uses — and it can cause real problems. Around 55% of stored data goes unused, which means you’re paying for storage and risking exposure without any benefit