22.1 Data Exchange in Windows

In general, Windows supports three mechanisms that applications can use to exchange data with one another:

Clipboard transfers

Dynamic-link libraries

Dynamic data exchange

Windows does not support sharing global memory handles directly. Because of expanded memory considerations, as well as compatibility with future versions of Windows, you should not dereference (by using the GlobalUnlock function), or otherwise manipulate, global memory handles created by another application. DDE is the only Windows mechanism that supports passing of global-memory handles between applications.