Dark data is all the stored information companies keep but never use—think old...

https://telegra.ph/What-Are-Common-Examples-of-Dark-Data-in-IT-Departments-07-31

Dark data is all the stored information companies keep but never use—think old files, logs, or emails piling up unnoticed. Surprisingly, 60-80% of data goes untouched, costing businesses around $2.5 million each year in storage and management