The Azure Active Directory Service (AADS) is a domain controller as a service to provide you with a DNS service and identity management. Central identity management is always an important part of security solutions. It enables the user to access the resources. On top of that, you can enforce policies and enable multi-factor authentication.
In the near future, it will be possible to use the Azure AD (AAD) as well. This is a completely different identity management system, without LDAP and Kerberos. In Linux, AAD will allow you to use your Azure credentials to log in to your virtual machine, but has no support on application level. So for now, AADS is a better idea.
In this section, we will focus on how to create the service and how to join the domain.