Dark data is the inactive or unused information stored in your systems—about...

https://www.bust-bookmark.win/dark-data-is-the-information-businesses-store-but-never-use-often-55-of-their

Dark data is the inactive or unused information stored in your systems—about 60% to 80% of it just sits there. This data isn’t just taking up space; it costs money to keep and can create noise that messes up AI projects