There's C, there's C++ and then there's MFC. 'MFC' stands for 'Microsoft Foundation Classes.' In this edition of the book, we won't get into Microsoft's new C# language at all.
The older style of Windows coding was called 'Win32.' Win32 code can in fact be incorporated into an MFC program, just like C code can be incorporated into any C++ program. So MFC is an extension of Win32 programming, just as C++ is an extension of C. MFC adds structure to Win32 at two levels: the low and the high. At the low level, MFC extends the Windows programming language by adding more types and more function names. At the high level, MFC makes it easy to automatically add a great many features to your programs by using the application frameworks, also known as AFX. In this subsection we'll talk primarily about MFC, and we'll talk about AFX below in Section 23.8: The MFC Program Flow.