Dark data is all the information your company keeps but rarely uses—around 55%...

https://www.bright-bookmarks.win/dark-data-is-the-hidden-info-your-team-isn-t-using-about-55-of-stored-data-is

Dark data is all the information your company keeps but rarely uses—around 55% of it just sits idle. This hidden data adds unnecessary costs, creates security risks, and clutters AI systems with noise