Dark data is all the inactive or unused information a company stores but never...

https://www.alphabookmarks.win/dark-data-is-the-info-companies-collect-but-never-use-it-can-be-60-80-of

Dark data is all the inactive or unused information a company stores but never analyzes. It can make up 60-80% of your data and typically costs businesses around $2.5 million each year in wasted storage and management