Dark data is the inactive or unused information your company keeps but doesn’t...

https://garrettsbestblogs.theglensecret.com/is-dark-data-ever-worth-monetizing-or-should-i-just-delete-it

Dark data is the inactive or unused information your company keeps but doesn’t analyze—around 60-80% of enterprise data. It can increase storage and backup costs and raise breach risks, including ransomware exposure