Read more at http://en.wikipedia.org/wiki/Robocopy.robocopy, or "Robust File Copy", is a command-line directory replication command. It was available as part of the Windows Resource Kit, and introduced as a standard feature of Windows Vista and Windows Server 2008.
Robocopy is designed for reliable mirroring of directories or directory trees. It has features to ensure all NTFS attributes and properties are copied, and includes additional restart code for network connections subject to disruption.