Dark data is the inactive information companies store but rarely use. It can be...

https://www.insert-bookmark.win/dark-data-is-the-inactive-information-your-business-collects-but-never-uses-it

Dark data is the inactive information companies store but rarely use. It can be as much as 60-80% of all stored data. This unused data takes up space and costs businesses millions—sometimes $2.5 million annually—in storage and management