1.3 Windows Libraries

Windows functions, like C run-time functions, are defined in libraries. The Windows libraries, unlike the C run-time libraries, are special dynamic-link libraries (DLLs) that the system links with your application when it loads your application. Dynamic-link libraries are an important feature of Windows because they minimize the amount of code each application requires.

Windows consists of the following three main libraries:

Library Description

User Provides window management. This library manages the overall Windows graphical environment, as well as an application's windows.
Kernel Provides system services, such as multitasking, memory management, and resource management.
GDI Provides the graphics device interface (GDI).