Hi,
You can refer to these links for more information on the different commands and how to use RoboCopy:
How to Use Robocopy to copy security information without copying any file data
http://support.microsoft.com/kb/323275
Return codes that are used by the Robocopy utility in Windows Server 2008
http://support.microsoft.com/kb/954404
You can also refer to:
http://en.wikipedia.org/wiki/Robocopy
Hope this helps