React Native is a framework that allows developers to build mobile apps using JavaScript, leveraging the same design principles as React. It provides pre-made UI libraries and components, such as icons, buttons, tabs, and forms, which can be customized later on. The React Native Vector Icons library offers over 3,000 icons, making it easy to extend, style, and integrate into projects. Other popular UI libraries include NativeBase, TComb Form Native, and React Native Elements. These libraries provide a wide range of components, including buttons, forms, lists, and more, which can be customized to fit specific needs. Additionally, the React Native documentation and community resources offer comprehensive guides, code snippets, and examples for developers to learn and implement these libraries in their projects.