Messages and Commands in the Framework
Applications written for Microsoft Windows are "message driven." In response to events such as mouse clicks, keystrokes, window movements, and so on, Windows sends messages to the proper window. Framework applications process Windows messages like any other application for Windows. But the framework also provides some enhancements that make processing messages easier, more maintainable, and better encapsulated.
The following topics introduce the key terms used in the rest of the article family to discuss messages and commands: