C++: What is the difference between CSIDL_DESKTOP and CSIDL_DESKTOPDIRECTORY?

What is the difference between passing CSIDL_DESKTOP and CSIDL_DESKTOPDIRECTORY to functions like SHGetSpecialFolderLocation?

CSIDL_DESKTOP is the virtual folder that represents the desktop

CSIDL_DESKTOPDIRECTORY special folder is a physical folder that contains the files that you think of as on your desktop

Programs shouldn't care about CSIDL_DESKTOPDIRECTORY; they should just operate on CSIDL_DESKTOP, because that's what the user sees

Ref:
What is the difference between CSIDL_DESKTOP and CSIDL_DESKTOPDIRECTORY? - The Old New Thing - Site Home - MSDN Blogs
CSIDL (Windows)