What Exactly Is a DLL?

Dynamic link libraries are program modules that contain code, data, or resources that can be shared among many Windows applications. One of the primary uses of DLLs is to enable applications to load code to execute at runtime instead of linking that code to the application at compile time. Therefore, multiple applications can simultaneously use the same code provided by the DLL. In fact, the files Kernel32.dll, User32.dll, and GDI32.dll are three DLLs on which Win32 relies heavily. Kernel32.dll is responsible for memory, process, and thread management. User32.dll contains routines for the user interface that deal with the creation of windows and the handling of Win32 messages. GDI32.dll deals with graphics. You'll also ...

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