(1) A unit within an organization, such as a company, that identifies a particular set of users.
(2) An Active Directory container object used within domains. An organizational unit is a logical container into which users, groups, computers, and other organizational units are placed. It can contain objects only from its parent domain. An organizational unit is the smallest scope to which a Group Policy object can be linked, or over which administrative authority can be delegated.
(3) A body whose data is to be kept separate from that of other, similar bodies. WebSphere BI for FN uses OUs to control access to resources, and to ensure data segregation. Typically, OUs are used to represent different financial institutions, or different departments within a financial institution.
(4) One of the types of subsidiary entities that can be added to an organization. Typically, organizational units are used to logically separate business units by function.