| Platform SDK: Active Directory, ADSI, and Directory Services |
ADSI is a set of COM interfaces that was created to make it easier for programmers to access disparate directory services. ADSI is built on a provider-based model. Clients use the COM interfaces exposed by ADSI. Providers implement the mapping between those COM interfaces and the underlying directory system. This abstraction saves the programmer from needing to know the API of a particular directory service, such as the Win32 API, for accessing the Windows NTŪ SAM, the LDAP API, for accessing the Active Directory, or the DAPI, for accessing the Exchange Server directory. Because ADSI is a set of COM interfaces, it can be used within Microsoft Visual C++, Microsoft Visual Basic, or any other COM-capable programming language.
Lightweight Directory Access Protocol (LDAP) is a standard Internet protocol for directory access. It is becoming the standard for directory access and interchange. LDAP is one of the providers included with ADSI. It is a wire protocol, which means that the conversation between an LDAP client and an LDAP server happens over a network. An LDAP client application can access any directory that exposes the LDAP protocol. The most current standard is LDAP version 3. Microsoft Exchange 5.5 supports LDAP version 3.
The following illustration depicts the relationship between these components:
The following topics are covered in this section: