Query execution is the process by which a database management system (DBMS) processes a request for data. When a user submits a query, the DBMS interprets it, optimizes the execution plan, and retrieves the requested information from the database. This involves accessing the relevant tables and applying any necessary filters or calculations. During query execution, the DBMS may use various algorithms to improve performance, such as indexing or caching. The goal is to return results as quickly and efficiently as possible, ensuring that users receive accurate data while minimizing resource usage. This process is crucial for applications relying on real-time data access.