An SQL Query Engine is a software component that processes and executes SQL (Structured Query Language) commands to interact with databases. It translates user queries into a format that the database can understand, retrieves the requested data, and returns the results. This engine optimizes the execution of queries to improve performance and efficiency. The SQL Query Engine works with various database management systems, such as MySQL, PostgreSQL, and Oracle. It handles tasks like parsing, planning, and optimizing queries, ensuring that data retrieval is done quickly and accurately. This makes it a crucial part of any data-driven application.