Final answer:
Domain forests are collections of domain trees that share a common AD DS.
Step-by-step explanation:
Collections of domain trees that share a common AD DS are called Domain Forests. A Domain Forest is a group of domain trees that are connected and share a common Active Directory Domain Services (AD DS) namespace. It allows for the consolidation and management of multiple domains within a single structure.
For example, let's say there are three domain trees called DomainA, DomainB, and DomainC. These domain trees are part of the same Domain Forest if they are connected and share a common AD DS namespace, such as forest.example.com.