Dark data is all the inactive information your company stores but never...

https://www.bookmarkmaster.win/dark-data-is-all-the-information-companies-collect-but-don-t-actively-use-often

Dark data is all the inactive information your company stores but never uses—often 60-80% of your data. It quietly eats up storage space and can cost businesses up to $2.5 million each year in wasted resources