What is the difference between ngMocks and TestBed?

Short answer: TestBed: Core Angular testing utility to configure test modules and components. ngMocks: A library built on top of TestBed to simplify mocking and reduce boilerplate by auto-mocking components, directives, pipes, and services.

Real-world example (ShopNest)

A shared CartService is injected into header and product pages so both see the same cart count.

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.