Flask SQLAlchemy is a powerful tool for building web applications that interact with relational databases in Python. It offers an intuitive interface for database operations, capitalizing on the capabilities of SQLAlchemy, a renowned object-relational mapping (ORM) library. With Flask SQLAlchemy, developers can create robust platforms to define data structures, execute queries, and manage database updates, including compatibility with various databases such as SQLite, MySQL, and PostgreSQL. The tool simplifies database interactions, aligns with object-oriented principles, and provides a structured way to manage changes to the database schema using Flask-Migrate. By combining Flask and SQLAlchemy, developers can streamline the database-driven web application development process, creating efficient and scalable applications.