You can place a set of users with the same administrative requirements into user groups. User groups make system administration much simpler, because you can assign all members of a group the same logon script, file rights and permissions, and user profile. If some aspect of the group's administrative requirements changes, you can make the change in just one place for all the users in the group.
User groups can be local or global. The terms local group and global group refer not to the contents of the group, but to the scope of the group's availability. A local group is available only on the domain controllers within the domain in which it is created, while a global group is available within its own domain and in any trusting domain. A trusting domain can, therefore, use a global group to control rights and permissions given members of a trusted domain.
A global group contains only individual user accounts (no groups) from the domain in which it is created. Once created, a global group can be assigned permissions and rights, either in its own domain or in any trusting domain. A global group is a good way to export a group of users as a single unit to another domain. For example, in a trusting domain you can grant identical permissions to a particular file to a global group, which then pertain to all individual members of that group.
Global groups are available only on Windows NT Server domains. When Windows NT Server is installed on a computer, it is configured with two predefined global groups:
A local group is a good way to import a group of users and global groups from other domains into a single unit for use in the local domain. A local group can contain user accounts or global groups from one or more domains. The group can be assigned privileges and rights only within its own domain. Local groups created on a Windows NT Workstation computer or a Windows NT Server computer in a workgroup are available only on that computer.
The following predefined local groups are available on Windows NT Workstation and Windows NT Server computers:
The following additional predefined local groups are available only on Windows NT Server computers acting as primary or backup domain controllers:
Another predefined local group, Power Users, is available only on Windows NT Workstation computers or on Windows NT Server computers that are not acting as domain controllers.