Dark data is all the information companies collect but never use—think files...

https://raymondsinterestingchat.quantlynix.com/posts/do-i-need-to-move-petabytes-to-the-cloud-to-get-value-from-dark-data

Dark data is all the information companies collect but never use—think files gathering digital dust. Around 55% of stored data goes dark, leading to wasted storage costs and extra security risks