Dark data is info stored but never used—think emails, old files, or inactive...

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

Dark data is info stored but never used—think emails, old files, or inactive databases. It can make up 55% of a company’s data and often hides risks like security problems or compliance issues