Dark data is the inactive or unused information sitting in your systems—often...

https://www.charliebookmarks.win/dark-data-is-the-inactive-or-unused-information-organizations-keep-but-don-t

Dark data is the inactive or unused information sitting in your systems—often 60% to 80% of it. It quietly drains budgets, wastes about $2.5 million annually for some firms, and adds noise that confuses AI projects