Chapter Summary

Inheritance can be used to organize classes into hierarchies.
Polymorphic variables are very powerful. Declared as one type, its static type, but can maintain a value of a different type, its dynamic type. Must be pointers or references.
When a virtual method is called using a polymorphic variable, its dynamic type is used.
A virtual method that is declared but not defined is called a pure virtual method. A class with a pure virtual method can not be instantiated. It is called an abstract class.