This chapter has provided you with some of the basics of how C# has implemented object-oriented programming. You saw how to create basic classes that expose fields, properties, and methods. In addition, you saw how to create object hierarchies using object inheritance, abstract classes, and polymorphism. Finally, this chapter provided a quick overview of creating and implementing interfaces. This chapter is far from the ultimate reference on object-oriented programming. However, it should give you enough basic information that you will be familiar with the OOP concepts and code used throughout the remainder of this book.