Conceptually, the Shell namespace may be regarded as a larger and more inclusive version of the file system.
The Shell namespace is a hierarchical tree that consists of the wide variety of objects that make up the system.
Specifically, the Shell namespace consists of two basic types of objects, namely files and folders.
For example, in Windows XP and other versions, "rundll32.exe" shell32.dll,Options_RunDLL 0 is executed on the command line when a user launches the "Folder Options" applet in the Control Panel.
The user's Desktop is a special folder that resides at the root of the Shell namespace.