Component (ICoffee):?

Short answer: This is the base interface that defines the common methods for the Cost() and Description() that every coffee component will implement. public interface ICoffee

Example code

{
double Cost();
string Description();
}

Real-world example (ShopNest)

Use a GoF pattern in ShopNest only when it removes duplication or makes a change safer—explain the problem it solves in the interview.

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.