An Execution Plan is a detailed roadmap that a database management system, like SQL Server or Oracle, creates to determine the most efficient way to execute a query. It outlines the steps the system will take, including how it will access data, join tables, and apply filters. This helps optimize performance by identifying the best methods for retrieving the requested information. Execution plans can be visualized using tools provided by database systems, allowing developers and database administrators to analyze and improve query performance. By understanding the execution plan, users can make informed decisions about indexing, query structure, and overall database design to enhance efficiency.