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

https://web-wiki.win/index.php/What_is_Data_Curation_and_How_is_it_Different_from_Data_Classification%3F

Dark data is the information companies collect but never use—think old files, emails, or log data sitting idle. It can make up 60-80% of all stored data, locking away hidden risks and costs. Ignoring dark data wastes time, space, and up to $2