What is the term for a group of related domains in Active Directory?

In Active Directory, a tree is defined as a collection of one or more related domains that share a contiguous namespace. This means that the domains within a tree have a hierarchical relationship and are interconnected based on their naming conventions. For example, if there is a root domain called "example.com," related domains might include "sales.example.com" and "hr.example.com."

Each domain in the tree can have its own security policies and administrative control, but they all function within a single directory structure that allows for efficient management and resource sharing. This structure helps simplify user access to resources across the different domains under the same tree, leveraging the trust relationships established between them.

The other options refer to different concepts within Active Directory. An organizational unit refers to a container used for grouping users and computers for policy application and administrative purposes; a domain denotes a single unit in Active Directory with its own security boundary; and an object is a more general term that can refer to any entity within Active Directory, including users, groups, or computers. Thus, in this context, the correct term for a group of related domains is a tree.