React Native and Flutter are both popular frameworks for building cross-platform mobile apps (Android and iOS) from a single codebase. React Native uses JavaScript (or TypeScript) and is backed by Meta. It connects to native components, making it easier for web developers to transition into mobile development. Flutter uses Dart and is backed by Google. It renders its own UI, which often leads to smoother performance and more consistent designs across platforms. In short: React Native is great if you already know JavaScript, while Flutter is better for high-performance, highly customized UI apps.