Dark data is all the info your team stores but rarely uses — think old files,...

https://high-wiki.win/index.php/How_Do_I_Estimate_the_Cost_of_Dark_Data_Storage%3F

Dark data is all the info your team stores but rarely uses — think old files, logs, and backups. Around 55% of stored data is “dark,” meaning it just sits there, costing money and storage space