What is reconciliation in react ?

During the reconciliation process, React compares the old and new virtual DOM trees and identifies the differences between them. Then, it updates the real DOM with only the necessary changes, instead of re-rendering the entire component tree. This process helps to improve the performance of the application by minimizing the number of updates needed to the DOM.

Reconciliation is a process in React that helps to optimize the rendering of components in the user interface. When a component's state or props change, React has to update the component and its children in the DOM. However, rather than re-rendering the entire component and its children, React attempts to optimize the rendering process by comparing the previous and current versions of the component tree and making only the necessary updates to the DOM.

In React, reconciliation refers to the process of updating the user interface to reflect changes in the underlying data model or component state. When a component's state or props change, React will compare the new data with the previous data and determine which parts of the component's UI need to be updated.

Reconciliation is a key feature of React that enables it to efficiently update complex user interfaces in response to changes in data or component state.

React uses a virtual DOM (Document Object Model) to optimize this process. When changes are made to the state of a component, React creates a new virtual DOM tree and compares it to the previous virtual DOM tree. The algorithm then determines which parts of the tree have changed and need to be updated in the real DOM.

The “reconciliation” algorithm in React is how the decision to re-render the component is made. In the browser, DOM manipulation is expensive and time consuming, both in mounting and unmounting. Part of what makes React very performant is its reconciliation algorithm.