The first domain that is created in Windows Server 2003 network is called the forest root domain. When
other domains are created on the network, they added to the root domain to form the tree structure or the
forest structure, depending on the domain name requirements.
A tree is a hierarchical arrangement of Windows Server 2003 domains that share a contiguous namespace.
In such an arrangement the root domain name is attached as a suffix to the new domain names. The new
domain is called a child domain of an existing parent domain and has a two-way, transitive trust
relationship with its parent domain.
A forest can either consist of a single tree or number of trees that do not share a contiguous namespace but
do share a common schema and global catalog. In this arrangement, every tree root domain has a transitive
trust relationship with the root domain. A single tree that is not related to any other tree constitutes a forest
of one tree. The root domain contains the configuration and schema data for all trees in the forest.
Both a tree and a forest are namespaces, which is a bounded area in which a name can be resolved. Using a
common namespace allows you to unify and manage multiple hardware and software environments in your
network. There are two types of namespaces:
Contiguous namespace. The name of the child object in an object hierarchy always contains the name
of the parent domain. A tree is a contiguous namespace because the name of any child object in a tree
always contains the name of the parent tree.
Disjointed namespace. The names of a parent object and of a child of the same parent object are not
directly related to one another. A forest is a disjointed namespace because all trees in a forest do not
share a common naming structure.