How does abstraction reduce complexity?

Short answer: Hides implementation details, exposing only what is necessary. Users interact with interfaces or abstract methods, not the full system logic. Simplifies testing, maintenance, and understanding of code.

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.