trust relationship

A logical relationship established between domains to allow pass-through authentication, in which a trusting domain honors the logon authentications of a trusted domain. User accounts and global groups defined in a trusted domain can be given rights and permissions in a trusting domain, even though the user accounts or groups do not exist in the trusting domain's directory. [Exchange 2003]

The relationship between two domains that enables a user in one domain to access resources in another domain. [Exchange 5.5]

A logical relationship established between domains to allow pass-through authentication, in which a trusting domain honors the logon authentications of a trusted domain.