For more information about the Azure Active Directory structure, see the Azure Active Directory documentation from Microsoft.
You must provide details about your organization the first time you register for a Microsoft cloud service. This detailed information is used to make a new Azure Active Directory directory partition. The organization represents one Azure Active Directory tenant. In One Identity Manager, you can edit the main data of each tenant. However, you cannot create new tenants in One Identity Manager.
A base domain is linked to the core directory in the cloud. You can also add other user-defined domains in Azure Active Directory, which you can then allocate to Microsoft cloud services. One Identity Manager only loads verified domain data into the database. It is not possible to edit data in One Identity Manager.