React works by creating a virtual representation of the user interface known as the virtual DOM (Document Object Model). Here’s how React works in a nutshell:
- Component Rendering: React organizes the UI into reusable components. Each component is responsible for rendering a part of the user interface.
- Virtual DOM: When a component’s state or props change, React creates a virtual representation of the updated UI called the virtual DOM. It’s a lightweight copy of the actual DOM.
- Diffing: React compares the previous virtual DOM with the updated virtual DOM to identify the differences or changes.
- Reconciliation: React determines the minimal set of DOM operations needed to update the actual DOM based on the differences found in the virtual DOM. This process is known as reconciliation.
- DOM Update: React applies the necessary DOM updates to bring it in sync with the virtual DOM, but only for the components that have changed. This selective update approach makes React highly efficient.
- Component Lifecycle Methods: React provides lifecycle methods that allow developers to define actions to be performed at specific stages of a component’s life, such as when it is mounted, updated, or unmounted.
- State Management: React allows components to manage their own state, which represents the data that influences the component’s behavior and appearance. When the state changes, React triggers a re-rendering of the affected component.
- Event Handling: React provides a synthetic event system that simplifies event handling. Developers can define event handlers directly in the components to respond to user interactions.
By efficiently updating only the necessary parts of the UI and abstracting away direct DOM manipulation, React minimizes the performance overhead and provides a smoother user experience.