So, imagine a domain and its NS records:
$ dig +short NS superuser.com ns-cloud-d1.googledomains.com. ns-cloud-d2.googledomains.com. ns-1699.awsdns-20.co.uk. ns-245.awsdns-30.com.
These 4 are name servers for superuser.com, this information (which nameservers domain uses) is obviously located on them, but there is this chicken egg problem. If you don't know any of these NS, where do you ask for their IP address? Authoritative DNS for whole "com" zone? If yes, where does that get it from and who has the authority to change that?
I also noticed that nameservers are part of WHOIS record, but are DNS server using that information in any way?
Domain Name: SUPERUSER.COM Registrar: NAME.COM, INC. Sponsoring Registrar IANA ID: 625 Whois Server: whois.name.com Referral URL: http://www.name.com Name Server: NS-1699.AWSDNS-20.CO.UK Name Server: NS-245.AWSDNS-30.COM Name Server: NS-CLOUD-D1.GOOGLEDOMAINS.COM Name Server: NS-CLOUD-D2.GOOGLEDOMAINS.COM