what is the difference between xcopy and robocopy
Robocopy, or "Robust File Copy", is a command-line directory and / or file replication command. Robocopy functionally replaces Xcopy, with more options. It has been available as part of the Windows Resource Kit starting with Windows NT 4.0, and was first introduced as a standard feature in Windows Vista and Windows Server 2008. The command is robocopy.