Husband, Father, IT Pro, service.
I ask a lot of questions to try to understand how people think.
I think I’m the most ridiculous, but for the same career reasons as the rest:
Active directory, yes, plus: Azure cloud sync with entra active directory Hybrid exchange on prem and office/exchange online.
For better or worse, large enterprise isn’t going away from M$.
Also, I have transparent proxy sophos IPS, security Onion IDS, Trellix ePO, and other security products all being integrated for info security testing.
Not suggesting this is normal, just my test/dev playground I don’t have to worry about breaking.
All the descriptions are right and techniques. Microsoft sometimes refers to this is split-brain and their documentation.
Organizations that choose not to do that use an active directory specific subdomain like some of the other comments mentioned. Example: adds. Company.tld.
Computer1.adds.company.tld. Dc1.adds.cimoany.tld.
Others doing split domain are
Adds.company.internal
Office culture nuances… I enjoy them.