What is integration testing and how is it different from unit testing?

Short answer: Integration testing verifies that multiple components or systems work together correctly, unlike unit testing which tests individual units in isolation. It focuses on interactions between modules, databases, APIs, or external services.

Example code

Integration testing verifies that multiple components or systems work together correctly, unlike unit testing which tests individual units in isolation. It focuses on interactions between modules, databases, APIs, or external services.

Real-world example (ShopNest)

ShopNest unit tests cover pricing and discount rules so a bad coupon change fails in CI before customers see it.

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.