What is a privacy budget?

Privacy budget is a concept from the field of differential privacy that limits the amount of information about data that can be disclosed when executing queries on a database or model. It measures how much 'privacy' can be spent to maintain a balance between data utility and confidentiality.

Each data query 'spends' part of the privacy budget, and when it is exhausted, further queries may lead to leakage of private information. This helps control the risk of revealing personal data during model training or data analysis.

Example: if you have a machine learning model trained with differential privacy, the privacy budget determines how much noise to add and how many queries can be made without revealing sensitive information about specific users.