Dark data is the inactive or unused information your business stores but...

https://www.strobe-bookmarks.win/dark-data-is-the-55-of-stored-information-companies-keep-but-do-not-use-this

Dark data is the inactive or unused information your business stores but doesn’t analyze. It can make up 55% of your data and often hides risks like ransomware exposure. Plus, storing and backing up this data wastes money—sometimes over $2