wikipedia.org:
https://en.wikipedia.org/wiki/Domain_Name_System

The DNS is just the addressing system. DNS settings are domain specific.
The applicable Requests for Comments require really technical specification.

Professional Domain Name System, eg:
https://dnsmadeeasy.com / https://constellix.com

Requirements for Domain Name Systems:

• Two-Factor-Authentication / several users
• Authorization by user name
• TLSA and CAA available
• Download print-out of setup
• History of changes
• Proper domain holder names

Example of checking software diversity of name servers:

$ dig +short NS nl | xargs -I% dig @% version.bind TXT chaos +short
“CIRA Server”
“Knot DNS 3.3.7”
“IPCom Anycast Network 1.0”

$ dig +short NS nl | xargs -I% dig @% hostname.bind TXT chaos +short
“LHR1”
“eqx-am-ns02-6194”
“tld-all-ams1”

Note: Redundancy with more than single DNS software is a topic for stability.

Example of Domain Name System settings, in Dutch: