Dark data is the unused information stored in your systems—often 55% or more of...

https://zaneznae304.lucialpiazzale.com/does-2-5-million-a-year-in-dark-data-waste-sound-realistic

Dark data is the unused information stored in your systems—often 55% or more of all enterprise data. It can increase storage and backup costs by millions annually and raises ransomware and breach risks since it’s rarely monitored