The Symfony React Video Chat application is a full-stack web application that enables users to create and join video chat rooms. The application uses the Twilio Programmable Video API to facilitate real-time video conferencing. It consists of two main components: a backend API built using Symfony, which generates access tokens for users and handles room connections, and a frontend React.js component, which renders the chat interface and connects to the backend API to retrieve access tokens and join rooms. The application also includes features such as user authentication, room creation, and participant connection tracking.