The Component Object Model (COM) is the foundation of much of the new Microsoft ActiveX technology, and after five years it's become an integral part of Microsoft Windows. So COM is now an integral part of Programming Visual C++. Soon, most Windows programming will involve COM, so you'd better start learning it now. But where do you begin? You could start with the Microsoft Foundation Class classes for ActiveX Controls, Automation, and OLE, but as useful as those classes are, they obscure the real COM architecture. You've got to start with fundamental theory, and that includes COM and something called an interface.
This is the first of seven chapters that make up Part IV of this book. Here you'll get the theory you need for the next six chapters. You'll learn about interfaces and how the MFC library implements interfaces through its macros and interface maps.