Dark data is the information your organization collects but never uses—often...

https://www.easybookmarkings.win/dark-data-is-the-55-of-stored-information-that-sits-unused-but-still-costs

Dark data is the information your organization collects but never uses—often making up 55% of stored data. This unused data not only wastes money on storage and backup but also increases risk by providing potential entry points for ransomware attacks