React is a JavaScript library used for building user interfaces, particularly for single-page applications (SPAs).
It is component-based, meaning the UI is broken down into reusable, independent pieces called components.
Key Working Principles of React:
1. Component-Based Architecture:
- Everything in React is a component.
- Components are reusable and composable.
- Each component has its own state and props.
2. Declarative UI:
- You describe the UI based on the state of the application, and React updates the DOM when the state changes.
- You don’t directly manipulate the DOM; instead, you tell React what the UI should look like, and React handles the DOM updates efficiently.
3. Unidirectional Data Flow:
- Data flows from parent components to child components via
props
. - State holds the data within a component, and when the state changes, React re-renders the component.
4. React’s Reconciliation Process:
- React uses a Virtual DOM and Diffing Algorithm to determine the minimal number of updates needed in the real DOM.