40 Debian Domain Name Example Update

The dns domain name is the part after the first dot.
Debian domain name example. You can check the fqdn using hostname fqdn or the domain name using dnsdomainname. I have a suse box too. Again there are some esoteric exceptions.
I am fuzzing over some details but close enough so the two questions are what to name the host and what to name the domain. Idealy the full hostname should be globally unique. What domain name and name servers do i use in debian install setup.
Domain name or host name. Dear list i have become confused about the domain name handling in debian.