Abstraction:?

Short answer: The Shape class is the abstraction. It holds a reference to the IDrawingAPI and delegates the drawing task to it. It defines the common interface Draw() that all shapes must implement.

Example code

public abstract class Shape
{ protected IDrawingAPI _drawingAPI; protected Shape(IDrawingAPI drawingAPI) => _drawingAPI = drawingAPI; public abstract void Draw();
}

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.