Unity Catalog is the built-in governance layer for Databricks, covering access control, data lineage, audit logging, and sensitive data protection across every workspace in your account. This article explains how Unity Catalog works using its three-level namespace, how to set up fine-grained permissions including row and column security, how lineage tracking works automatically, how to meet compliance requirements like GDPR and HIPAA, and the most common mistakes teams make when implementing it. If you are building on Databricks in 2026 and governance is still an afterthought, this article is your starting point.