Dark data is the information companies store but rarely use—up to 60%-80% of it...

https://www.bookmarking-keys.win/dark-data-refers-to-the-55-of-stored-information-that-businesses-collect-but

Dark data is the information companies store but rarely use—up to 60%-80% of it sits inactive. This unused data can rack up storage costs, create security risks, and add noise that throws off AI projects