Dark data is all the info your company collects but never uses—up to 55% of it....

https://wiki-neon.win/index.php/Dark_Data_and_AI_Governance:_What_Should_Be_Blocked_from_Ingestion%3F

Dark data is all the info your company collects but never uses—up to 55% of it. This inactive data isn’t just wasting storage; it can cost you millions and create noise that confuses AI systems