Cross-database queries with REST APIs make it easier to access and analyze data stored in multiple databases without physically moving it. Here's why this matters: What it Does: It allows you to query different databases (e.g., PostgreSQL, MongoDB, MySQL) through a single interface. Why it Works: REST APIs provide a secure and standardized way to connect databases, enabling seamless data integration. Key Benefits: Challenges include performance issues, data format inconsistencies, and security risks.