User guide

Glossary 260
in the same domain. Running a domain controller in the Mixed Domain Mode does not affect its ability to
replicate and interact with Windows® 2000-based servers in other domains.
name resolution
The process of translating a name into some object or information that the name represents. Active
directory forms a name space in which the name of an object in the directory can be resolved into the
object itself.
name space
A name or group of names that are defined according to some naming convention. Any bounded area in
which a given name can be resolved. Active directory is primarily thought of as a name space, as is any
directory service.
Native Domain Mode
For Windows® 2000, Native Domain Mode refers to a configuration of active directory that allows
domain controllers for a given domain to run under Windows® 2000 only. For Windows Server™ 2003,
domain controllers for a given domain are allowed to run under Windows® 2000 or Windows Server™
2003. This mode allows active directory to enable features, such as nested global groups, that are not
possible under Mixed Mode operation. See also Mixed Domain Mode and functional levels.
object
An active directory object is a distinct, named set of attributes that represents something concrete, such as
a user, a printer, a network console switch, or an application. The attributes hold data describing the
thing that is identified by the directory object. Attributes of a user might include the user's given name,
surname, and e-mail address.
object class
Each object class is a structure defined in the active directory schema and subsequently used to describe
the attributes and other schema requirements associated with a particular type of object (for example,
Object Class = User).
organizational unit
Each OU created in active directory is a container that is an active directory administrative boundary,
controlled by group policy. OUs can contain users, groups, resources, and other OUs. An OU can be
thought of as providing the administrative functionality found in Windows NT® 4.0 domains. In other
words, the administrative control provided by Windows NT® 4.0 domains has been incorporated into
active directory organizational units.
Peer Master Domain Controller
A domain controller is called a Peer Master Domain Controller if it a controller for a domain that has
more than one domain controller. It is called a "peer master" for the domain because it can be modified
(unlike BDC under the older Windows NT® 4.0 network architecture). Each peer master for a domain
replicated data modifications it receives to communicate the changes to all the other peer masters in the
same domain. Under the older Windows NT® 4.0 network architecture, only the PDC can be written to
and the BDCs are read-only. Under active directory, every domain controller for a given domain can be
written to and is responsible for replicating changes to the other Peer Master Domain Controllers for the
same domain.