This question already has an answer here:

What are the differences between different types of symbolic link in Windows?

The Microsoft website tells me;

/d Creates a directory symbolic link. By default, mklink creates a file symbolic link. 
/h Creates a hard link instead of a symbolic link.
/j Creates a Directory Junction.

I'm still none the wiser as to what the differences are between a directory symbolic link, a hard link and a directory junction.

marked as duplicate by paradroid, harrymc windows-7 May 27 '14 at 6:46

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.