"Special folders" refers to directories in the Windows operating system that provide extended functionality in the user interface. Prominent examples are the "Desktop", "Start Menu", the "My Documents" and the "Fonts" folders.
The physical location and the number of special folders depend on the Windows version and system language.
Windows transparently manages the correlation between physical location on the disk and representation in the shell namespace, so these folders are best retrieved through the Windows API, as opposed to using fixed paths.