React does not have a native canvas element. The <canvas> tag is a DOM element, and the drawing context is an imperative API that sits outside React’s declarative model. Interactivity—detecting a click on a shape, hovering over a pixel, dragging a node—requires translating DOM events into coordinates that the canvas understands, and then deciding whether…

React Three Fiber is a React renderer for three.js, not a wrapper library. It does not add an abstraction layer between React and the 3D scene; it replaces the DOM as the rendering target. The component tree you write is the scene graph, and mounting a <mesh> creates a THREE.Mesh that is added to the…

React’s component model is not bound to the browser. The same reconciliation engine that renders to the DOM in a web application can render to a Chromium window embedded in a desktop process, or to the operating system’s native webview. The two dominant frameworks that make this possible are Electron and Tauri, and they represent…

React Native applications are rarely a single screen, and they frequently need capabilities that JavaScript cannot provide. Navigation is the framework’s answer to the first problem: a navigator manages the presentation and transition between screens. Native modules are the answer to the second: a bridge that exposes platform APIs—camera, Bluetooth, secure storage—to JavaScript. Both are…

React Native is not React running in a browser. It is a framework that uses the React programming model to describe a native view tree, and at runtime it creates the actual platform views—UIView on iOS, android.view.View on Android—that the operating system renders. The JavaScript you write looks like React, but the primitives are different,…

A reusable component library is not a folder of .tsx files copied between projects. It is a package with a stable public API, a build that produces both ESM and CommonJS output, a set of peer dependencies that prevents duplicate React instances, and a development environment where every component can be rendered in isolation. The…

A React monorepo is not a repository with multiple package.json files. It is a repository where the dependency graph between packages is known, where a change to a shared UI component triggers only the builds and tests that depend on it, and where the CI pipeline finishes in seconds rather than minutes because the cache…

An offline-first application assumes the network is unreliable and designs for that assumption from the start. It loads from a local cache, writes to local storage immediately, and synchronizes with the server when connectivity returns. React does not provide this behavior natively; the browser does, through two APIs that work outside the component tree: the…

A WebSocket is a persistent, bidirectional connection between the browser and a server. Unlike HTTP, where every request opens a new connection and waits for a response, a WebSocket stays open and allows either side to send data at any time. React does not have a built-in WebSocket abstraction, and the browser’s WebSocket API is…

A React component that manages complex interaction logic with useState and useEffect is, in the formal sense, an infinite state machine. Any combination of boolean flags and nullable values can occur, including combinations that should be impossible. XState replaces that open-ended model with a finite state machine: a declared set of states, a declared set…