AD LDS(Active Directory Lightweight Directory Services) on Windows 7.

Active Directory Lightweight Version (AD LDS) is now available for Windows 7 also.AD LDS provides directory services for directory-enabled application. Administrators will be able to see this version without the domain control oversight.AD LDS comes with support for Windows 7 Enterprise; Windows 7 Professional and Windows 7 Ultimate.

AD LDS independently provides directory storage and access for applications, so AD LDS uses the same standard application programming interfaces (APIs) as the full functioning Active Directory to manage and access the application data. The benefit for application that requires directory services, but do not require the complete infrastructure features of Active Directory is less overhead at the client level.

Active Directory Technologies: Full and Lightweight

• Administrators have a choice of which DS to use. Both AD LDS and AD DS use the same core directory service technologies, but they are designed to address different needs in an organization.
• Domain and Forest: The structure of AD DS allows it to be used throughout the entire forest. This provides directory services for both the Windows server operating system and for directory-enabled applications. For the server operating system, AD DS stores critical information about the network infrastructure, users and groups, network services, and so on.
• Applications: AD LDS provides directory services specifically for directory-enabled applications.  AD DS domains or forests are not necessary. However, in environments where AD DS exists, AD LDS can use AD DS for the authentication of Windows security principals.
• AD LDS and AD DS can run concurrently in the same network. In addition, AD LDS can support both domain users and workgroup users simultaneously.

An instance of Active Directory Lightweight Directory Services (AD LDS) is a single running copy of AD LDS. Multiple copies of AD LDS can run simultaneously on the same computer. This is not true for AD DS, the full service. This improves availability and load balancing when instances are replicated across multiple servers. Multiple instances of AD LDS have their own separate directory, as well as a unique service name, and a unique service description that is assigned when the instance is created. Duplication or conflicts are avoided this way.