What are React's key features?

React's key features include:

1. Component-Based Architecture: React allows developers to build encapsulated components that manage their own state, promoting reusability and modularity.

2. Virtual DOM: React uses a virtual representation of the DOM to optimize rendering. It updates only the parts of the UI that have changed, improving performance.

3. Declarative UI: React enables developers to describe how the UI should look based on the current state, making the code more predictable and easier to debug.

4. Unidirectional Data Flow: Data in React flows in one direction, from parent components to child components, which helps in managing the application state more effectively.

5. Hooks: React provides hooks, such as useState and useEffect, which allow developers to use state and lifecycle features in functional components.

6. JSX Syntax: React uses JSX, a syntax extension that allows developers to write HTML-like code within JavaScript, making it easier to visualize the UI structure.

7. Ecosystem and Community: React has a large ecosystem of libraries and tools, along with a strong community, providing extensive resources and support for developers.

8. Server-Side Rendering (SSR): React can be rendered on the server side, improving performance and SEO for web applications.

These features make React a popular choice for building modern web applications.