Back in the year 2000, when Active Directory was introduced to the larger public, we lived in a different world. The internet was only just starting to deliver value to businesses. That's why, in Windows 2000 Server, Active Directory was largely disconnected from the internet. Windows 2000 Server's default Domain Name System (DNS) settings even came with a root domain; so, if you wanted to connect to the internet, you'd need to delete the . DNS zone manually.
Fast forward to today, and the internet and cloud services seem omnipresent. The default . DNS zone has disappeared from Windows Server, but the concepts of trees and forests in Active Directory has persisted, and they still allow for some confusion ...
