Metastores and catalogs are interchangeable terms in Azure Databricks, both serving the same purpose of metadata storage and access control.

Metastores in Azure Databricks are primarily used for storing metadata of data sources, such as tables and schemas, while catalogs are designed to manage access control and security policies, ensuring compliance with data governance standards.

Catalogs serve as the sole repository for all metadata in Azure Databricks, eliminating the need for metastores in data governance strategies.

Metastores and catalogs have no role in data governance within Azure Databricks, as these functions are managed externally by Azure Active Directory.