By default, users authenticate and can access resources in their domain. Trusts enable cross-domain and cross-forest resource access and authentication. Table 4-2 lists several trust relationships.
TABLE 4-2 Trust relationships
An important concept to understand is trust transitivity, in which trust propagates between trusted resources to other resources. For example, when a forest trust is created between two forests in a transitive manner, that trust then extends to all domains within each forest.
Contrast this with a non-transitive trust, whereby the trust relationship exists solely between the domains participating in the relationship.
