Differential privacy is a formal mathematical definition for privacy that guarantees the output of a data analysis or machine learning algorithm does not reveal whether any single individual's data was included in the input dataset. It achieves this by injecting carefully calibrated statistical noise into query results or model updates, providing a quantifiable privacy budget (epsilon, ε) that bounds the maximum potential privacy loss. This framework is a cornerstone of privacy-preserving machine learning, enabling useful insights to be extracted from sensitive datasets while providing individuals with robust, mathematically proven protection against re-identification.
