Inheritance & Polymorphism

A derived class reuses and extends a base class:

class Vehicle { public: void honk() const { std::cout << "Beep!\n"; } protected: std::string brand_ = "Generic"; };

class Car : public Vehicle { public: void describe() const { std::cout << brand_ << " car\n"; } };

Car c; c.honk(); c.describe();

Inheritance models an "is-a" relationship: a Car is a Vehicle.