Active Directory (AD) is an implementation of LDAP directory services by Microsoft for use primarily in Windows environments. Its main purpose is to provide central authentication and authorization services for Windows-based computers. Active Directory also allows administrators to assign policies, deploy software, and apply critical updates to an organization. Active Directory stores information and settings in a central database. Active Directory networks can vary from a small installation with a few hundred objects, to a large installation with millions of objects.    Read More >>

Active Direcory management programs can be written using two methods.

i.  Using the WinNT provider
ii. Using the LDAP provider

The WinNT provider is the older one and it is designed for Windows NT domains. LDAP is the latest and can manage Windows Domains equal to or higher than Windows 2000. The following is a brief comparison between WinNT and LDAP.

WinNT	LDAP
Dessigned for Windows NT domains	Designed for Windows 2000 and higher
Exposes fewer attributes	Exposes all attributes
Slower and less efficient	Faster and Efficient
Supports flat name space	Supports hierarchichal name space
Cannot recognoze Organizational Units	Can recognize OUs
Does not support nested global and universal security groups	Supports all kinds of nested groups
WinNT can be used to access LDAP active directory	LDAP cannot be used to access WinNT SAM database
Can manage local accounts on computers/servers	Cannot be used to manage local accounts on computers/servers