What's NTDSUTIL? When do you use it?

NTDSutil is a Windows utility for configuring the heart of Active Directory. Ntdsutil.exe is a command-line tool that provides management facilities for Active Directory .Use Ntdsutil to perform database maintenance of Active Directory, to manage and control single master operations, and to remove metadata left behind by domain controllers that were removed from the network without being properly uninstalled. By default, Ntdsutil is installed in the Winnt\System32 folder.