What is TestBed in Angular, and how is it used?

Short answer: TestBed is the primary API to configure and initialize the environment for unit testing Angular components and services. It allows you to declare components, provide services, import modules, and compile templates.

Real-world example (ShopNest)

ShopNest admin can be built in Angular with modules/components, services for API calls, and reactive forms for product edit.

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.