Azure AD Connect
Azure Ad Connect is a tool provided by Microsoft that allows to extend the scope of AD accounts for cloud services. Indeed the AD user accounts can be used only in an AD domain. To allow a user to use the login and password in a cloud service (Azure, EMS, Office 365,…) it is necessary to proceed with the synchronization of accounts. Several solutions are possible, using ADFS server, the password synchronization or Azure AD pass-through). The tool can be installed on a domain controller or a member (joined to the domain or workgroup) server.
It is possible to synchronize multiple AD forests for a same nevertheless requirements are to be respected.