What is reconciliation and why is it important?

Short answer: Reconciliation is the process React uses to update the UI efficiently when state or props change.

Explain a bit more

React compares the old virtual DOM with the new virtual DOM and calculates the minimal set of changes required to update the real DOM. This makes React apps fast and efficient. Why important: It helps React determine the minimal updates needed, avoiding unnecessary re-renders. React uses a diffing algorithm to compare previous and current states to optimize DOM updates.

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.