First off all let me apologize if this question has been answered before.
I'd like to know if a nameserver domain name, for instance, ns1.MyDoamain.com, is something more than a A Record pointing to the IP of the namerserver.
I know that when I want to have MyDomain.com using the nameservers ns1.MyDomain.com and ns2.MyDomain.com I have to ask my registrar to register ns1.MyDomain.com and ns2.MyDomain.com as nameservers, before I can use them. But suppose MyDomain.com uses ns1.OtherDomain.com and ns2.OtherDomain.com as nameservers, can I simply create two A records for ns1.MyDomain.com and ns2.MyDomain.com and use them as nameservers for other domains?
The reason you need to register nameservers with your registrar is so the root servers can provide "glue" (in other words, if you have example.com delegated to ns1.example.com and ns2.example.com, the .com servers need to serve A records for ns1 and ns2, so that resolvers know where they are). If you don't register ns1.mydomain.com and ns2.mydomain.com, then registrars won't let you delegate domains to them. That being said, there's no technical reason that this is necessary (although it takes less work to perform a query if the root servers are providing glue records containing your nameservers).