Symfony is a powerful open-source PHP web development framework designed to make developing web applications easier. It provides developers with a set of tools and components that can be used to create robust, high-performance, and secure web applications in a fraction of the time. With features like high-performance architecture, advanced security, and scalability, Symfony is a great choice for developers looking to create powerful web applications fast. Additionally, because of its open-source nature, developers can customize and extend Symfony with a variety of third-party plugins and libraries. It's no wonder Symfony has become one of the most popular frameworks for developing modern web applications.