Dark data refers to the 55% of stored information that organizations keep but...

https://www.start-bookmarks.win/dark-data-is-the-inactive-or-unused-information-that-piles-up-in-your-storage

Dark data refers to the 55% of stored information that organizations keep but don’t use. Holding onto this inactive data not only wastes storage and backup resources but also increases risks like ransomware exposure