Dark data is the unstructured, inactive information companies store but rarely...

https://www.deltabookmarks.win/dark-data-refers-to-the-55-of-stored-information-that-organizations-keep-but

Dark data is the unstructured, inactive information companies store but rarely use—think old emails, logs, or files. It can make up 60-80% of all data, yet it often sits forgotten, driving up storage costs and creating compliance risks