What is reconciliation in React?

Short answer: Reconciliation is the process by which React updates the DOM efficiently when a component's state or props change.

Explain a bit more

React uses a virtual DOM to compare the new virtual DOM tree with the previous one and determines the minimal set of changes required to update the actual DOM. Key Concepts: Virtual DOM: A lightweight representation of the real DOM. Diffing algorithm: React’s algorithm compares the old and new virtual DOMs to find the differences (diffs) and apply the smallest set of changes. Reconciliation Flow:

Real-world example (ShopNest)

ShopNest’s storefront is React: components for ProductCard, CartDrawer, and CheckoutForm, with hooks for local UI state.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.