Turbo Modules

Deep linking is the ability to direct users to a specific screen or content within a mobile or web application via a URL, rather than just opening the app's home screen. In React Native and Flutter, this involves configuring URL schemes (e.g., `myapp://profile/123`) or universal/app links that work across platforms. Deep linking is essential for push notification routing, marketing campaigns, sharing content between users, and creating seamless web-to-app transitions.

A WebView is an embeddable browser component that renders web content (HTML, CSS, JavaScript) inside a native mobile application. It allows developers to reuse existing web code within a native app shell, commonly used for displaying rich content, integrating web-based features, or building hybrid apps. While convenient, WebView-heavy apps typically have worse performance and a less native feel compared to truly native or React Native/Flutter approaches.

Hermes is an open-source JavaScript engine developed by Meta, optimized specifically for running React Native applications on mobile devices. It uses ahead-of-time (AOT) compilation to convert JavaScript into bytecode during the build process, resulting in faster app startup times, reduced memory usage, and smaller app sizes compared to JavaScriptCore. Hermes is now the default JavaScript engine for React Native and also supports iOS since React Native 0.70.

React Native is a framework for building native mobile applications for iOS and Android using React and JavaScript/TypeScript. Unlike hybrid approaches that render in a WebView, React Native maps React components to actual native platform UI elements, providing native look, feel, and performance. Its "learn once, write anywhere" philosophy allows web developers to leverage their React knowledge for mobile development while still accessing platform-specific APIs when needed.

Hot reload is a development feature that injects updated code into a running application without restarting it or losing the current state. In Flutter, hot reload works by injecting updated Dart source code into the running Dart VM, typically completing in under a second. React Native offers a similar feature called Fast Refresh that preserves component state during edits. Both dramatically accelerate the development feedback loop compared to traditional compile-and-restart cycles.

Styled Components is a popular CSS-in-JS library for React and React Native that uses tagged template literals to style components. It automatically generates unique class names, supports dynamic styling based on props, handles vendor prefixing, and provides full theming capabilities. The library colocates styles with components, making it easy to understand what each component looks like and to delete styles safely when removing components.