Dark data is the stuff companies store but rarely use—think old emails, logs,...

https://charlie-wiki.win/index.php/What_is_a_Global_Metadatabase_and_Why_Would_I_Want_One%3F

Dark data is the stuff companies store but rarely use—think old emails, logs, and unused files. It makes up about 60 to 80% of stored data but sits inactive, taking up space and costing money. For example, businesses can waste up to $2