A data catalog is a centralized repository that stores metadata about an organization's data assets, making it easier for users to discover, access, and understand the data available within the organization. These catalogs help users find relevant data sources, understand their structure and content, and determine their suitability for specific use cases. Data catalogs also facilitate data governance by providing visibility into data assets, ensuring data quality and compliance with regulations. They are commonly used in data management, data governance, and data analytics initiatives within organizations to improve data accessibility, usability, and trustworthiness.