In Active Directory, what is an organizational unit?

An organizational unit (OU) is a subdivision within an Active Directory into which you can place users, groups, computers, and other organizational units. You can create organizational units to mirror your organization's functional or business structure. Each domain can implement its own organizational unit hierarchy. If your organization contains several domains, you can create organizational unit structures in each domain that are independent of the structures in the other domains.

The term "organizational unit" is often shortened to "OU" in casual conversation. "Container" is also often applied in its place, even in Microsoft's own documentation. All terms are considered correct and interchangeable.

At Indiana University, most OUs are organized first around campuses, and then around departments; sub-OUs are then individual divisions within departments. For example, the BL container represents the Bloomington campus; the BL-UITS container is a subdivision that represents the University Information Technology Services (UITS) department on the Bloomington campus, and there are subcontainers below that. This method of organization is not an enforced rule at IU; it is merely chosen for convenience, and there are exceptions.

Some of this information was adapted from Microsoft support documentation, available at:

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