React

React 16 introduced us to Fiber and hooks. React 18 brought concurrent rendering. And React 19? Well, it's redefining how we think about data fetching and server components entirely.

Discover the new features in React 19 including the compiler, actions, and optimistic updates.

State is the heart of interactive React applications. Without state, your components would be static - unable to respond to user input, update based on network responses, or change over time. The `useState` hook is React's primary mechanism for adding state to function components.

`useRef` is a **mutable container that persists across renders without triggering re-renders**. This property makes it essential for DOM access, but equally powerful for storing any value that needs to survive re-renders without affecting the render cycle.