Why is abstraction important?

Short answer: Simplifies complex systems by exposing only relevant functionality. Enhances maintainability, readability, and reusability of code. Reduces dependency on implementation details, making systems more flexible.

Real-world example (ShopNest)

Checkout calls IPaymentGateway.Charge(). Razorpay and Stripe adapters implement the same interface, so ShopNest can switch gateways without rewriting the order service.

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.