What term is used for a collection of Active Directory domains that share a common schema and configuration?

The term used for a collection of Active Directory domains that share a common schema and configuration is "Forest." In Active Directory architecture, a forest represents the top-level container and can include one or more domains. It is designed to provide a unified namespace and a shared directory service across all domains within that forest, allowing for resource sharing and management at a higher level.

In a forest, all domains share a schema, which is the structure that defines the types of objects and attributes that can be stored in the directory. This means that any changes made to the schema within the forest are visible to all domains, ensuring consistency across the organization.

The other terms refer to different concepts within the context of Active Directory. A domain refers to a single logical grouping of objects like users and computers. A workgroup is typically a simple networking arrangement for a small group of computers that do not require centralized management or directory services. Hierarchy in this context might refer more broadly to the organizational structure of a domain or forest but does not specifically define the collection of domains as a forest does.