There are two types of groups in Active Directory: distribution groups : You can use distribution groups to create e-mail distribution lists security groups. security groups to assign permissions to shared resources like printers ,scanners ,servers etc.
â– Security groups Security groups are used to group domain users into a single administrative unit. Security groups can be assigned permissions and can also be used as e-mail distribution lists. Users placed into a group inherit the permissions assigned to the group for as long as they remain members of that group. Windows itself uses only security groups.
â– Distribution groups These are used for nonsecurity purposes by applications other than Windows. One of the primary uses is within an e-mail
As with user accounts, there are both local and domain-level groups. Local groups are stored in a local computer's security database and are intended to control resource access on that computer. Domain groups are stored in Active Directory and let you gather users and control resource access in a domain and on domain controllers
There are two group types in Active Directory: security and distribution.
A security group:can be used to apply permissions to objects for the members of the group.
A distribution group, on the other hand, cannot be used for permissions but is used instead to send mail to members of the group.
Group scope in Active Directory is defined as follows:
Machine Local Groups-Machine local groups:, also known as simply "local groups," previously existed in Windows NT 4.0 and can theoretically contain members from any trusted location. Users and groups in the local domain, as well as in other trusted domains and forests, can be included in this type of group. However, it is important to note that local groups allow resources to be accessed only on the machine where they are located, which greatly reduces their usability.
Domain Local Groups-Domain local groups: are essentially the same thing as local groups in Windows NT, and are used to administer resources located only on their own domain. They can contain users and groups from any other trusted domain but are available only in native Windows 2000 domains. Most typically, these types of groups are used to grant access to resources for groups in different domains.
Global Groups-Global groups are on the opposite side from domain local groups. They can contain users only in the domain in which they exist but are used to grant access to resources in other trusted domains. These types of groups are best used to supply security membership to user accounts that share a similar function, such as the sales global group.
Universal Groups-Universal groups can contain users and groups from any domain in the forest and can grant access to any resource in the forest. Along with this added power come a few caveats. First, universal groups are available only in Native mode domains. Second, all members of each universal group are stored in the global catalog, increasing the replication load. It is important to note, however, that universal group membership replication has been noticeably streamlined and optimized in Windows .NET Server 2003 because the membership is incrementally replicated.
Types of Groups
Although groups are covered in more detail in Chapter 6, the type of group used (domain local, global, or universal) has significant impact on replication of group objects for large multidomain organizations as well as organizations with sites connected through slow links.
For a single domain organization with high-speed connections to all sites, domain local, global, and universal groups are effectively the same because the organization has only one domain, and replication occurs at high speeds to all domain controllers.
However, in a multidomain environment, by default, only the group name of a global group replicates between domains, not the membership names. Therefore, if a user in one domain wants to view the member list of a global group in another domain, the user's request will have to query across a WAN to the other domain to view the membership of the global group.
Universal groups, on the other hand, do replicate group membership information between domains, so a user query of a universal group membership list will be immediately available in the user's local domain. However, because universal group membership replicates between domains, if a list of group members is not needed to replicate between domains, traffic can be minimized by simply making the group a global group.
In Windows Server 2011 it is called Active Directory.
Active Directory
Windows 7 Professional can be added to an Active Directory domain. the other versions has issue and many of the feature not available to run AD correctly
the Domain is called as the security boundary with in the active directory. A Windows domain is a logical group of computers running versions of the Microsoft Windows operating system that share a central directory database. domain governs the way user access resources of the network
windows nt 4 and windows 2000
the Domain is called as the security boundary with in the active directory. A Windows domain is a logical group of computers running versions of the Microsoft Windows operating system that share a central directory database. domain governs the way user access resources of the network
The Restartable Active Directory, that allows you to have the ntds.dit in offline mode WITHOUT rebooting the domain controller.
Domain Controller
Active Directory was previewed in 1999, released first with Windows 2000 Server edition, and revised to extend functionality and improve administration in Windows Server 2003. Additional improvements were made in Windows Server 2003 R2. Active Directory was refined further in Windows Server 2008 and Windows Server 2008 R2 and was renamed Active Directory Domain Services. Active Directory was called NTDS (NT Directory Service) in older Microsoft documents. This name can still be seen in some Active Directory binaries.
Windows 2000 Mixed: This is the default functional level
Active Directory Services is included with most Windows systems as it is a product of Microsoft. It is often used with Windows domain networks, authorizing computers within the network.
Restartable Active Directory