Dark data is the untouched information stored in your systems—up to 55% of all...

https://www.coast-bookmarks.win/dark-data-is-all-the-info-stored-but-never-used-like-inactive-files-or-old

Dark data is the untouched information stored in your systems—up to 55% of all data goes unused. This matters because it racks up costs and creates risk, especially when AI sifts through cluttered files