Tortoise-ORM is an asynchronous object-relational mapper for Python that lets you interact with SQL databases (MySQL, PostgreSQL, SQLite) using async/await syntax. It's designed to handle relational data with built-in support for relationships between models, making it useful when you need non-blocking database operations in async Python applications. You would use it to write database code that doesn't block your event loop while maintaining clean, object-oriented data modeling.