Reconciliation in ReactJS is a fundamental process by which React updates the Document Object Model (DOM) to reflect the most recent state of a React application's components. This process is crucial for ensuring that the user interface remains efficient and responsive to user interactions and state changes within the application.
Key Components of Reconciliation
Virtual DOM: React maintains a virtual representation of the DOM, known as the Virtual DOM. This is a lightweight copy that allows React to quickly determine changes without affecting the actual DOM initially[1][6].
Diffing Algorithm: When a component's state or properties (props) change, React creates a new Virtual DOM tree. The reconciliation process involves a "diffing" algorithm where this new Virtual DOM tree is compared with the previous tree[1][4]. The algorithm identifies what has changed between the two trees.
Minimizing Updates: The primary goal of reconciliation is to minimize the number of updates to the actual DOM, which is a costly operation in terms of performance. React achieves this by updating only the parts of the DOM that have actually changed[1][4].
How Reconciliation Works
Render Phase: Initially, when a component's state or props change, React re-renders the component, generating a new Virtual DOM[3].
Comparison: The new Virtual DOM is then compared with the previous version. React uses the diffing algorithm to detect differences and determines the minimal set of changes required to update the actual DOM[1][4].
Update Phase: React then updates the actual DOM only where necessary, rather than re-rendering the entire DOM tree. This selective update process significantly ...
