The core of the Microsoft Foundation Class Library is an encapsulation of a large portion of the Windows API in C++ form. Library classes represent windows, dialog boxes, device contexts, common GDI objects such as brushes and pens, controls, and other standard Windows items. These classes provide a convenient C++ member function interface to the structures in Windows that they encapsulate. For more about using these classes, see Window Object Topics in the Visual C++ Programmer's Guide.
But the Microsoft Foundation Class Library also supplies a layer of additional application functionality built on the C++ encapsulation of the Windows API. This layer is a working application framework for Windows that provides most of the common user interface expected of programs for Windows, including toolbars, status bars, printing, print preview, database support, and ActiveX support. Using the Classes to Write Applications for Windows in Visual C++ Programmer's Guide explains the framework in detail, and Visual C++Tutorials provides the Scribble tutorial, which teaches application-framework programming.