React Native is an open-source framework developed by Facebook for building mobile applications using JavaScript and React. It allows developers to write code once and deploy it to both iOS and Android platforms, offering a native-like experience. React Native combines the flexibility of JavaScript with the performance of native components, enabling the creation of high-quality, cross-platform mobile apps. It also supports hot reloading, which speeds up development by allowing real-time code updates without restarting the app. React Native is widely used for its efficiency, large community, and strong ecosystem.