On member servers and Windows® 2000 Professional, there is a local security database. That local security database can contain its own local users whose scope is only the particular computer where they are created. When managing these types of users on member servers and workstations, you use the WinNT provider.
When managing users on a Windows 2000 domain using ADSI, you use the LDAP provider. When managing users on member servers and workstations, you use the WinNT provider.