DNS Question
 

When you see a server named ns1.domain.com, what does the ns stand for? Is this just a standard way of naming a DNS server?

its to do with dns heighrachy.

in effect this is saying i am the primary name server for domain.com, (being the root server for that domain space.)

the secondary would be ns2.domain.com


maybe this will help:

http://www.sprint.net/support/dns.html

Ummm---I think that this is a convention and not part of any fundamental protocol. i.e. the servers could just as well be named fred.domain.com, and nancy.domain.com

Is there not also a thing called subdomains--such that if an IP maps to "domain.com", that one can still address "subdomain1.domain.com" and "subdomain2...." etc.??

You are absolutely correct. It is in fact a naming convention and has nothing to do with the functionality of DNS. In the example of ns1.domain.com, ns1 is simply a subdomain of domain.com. If you had linux.rocks.the.house.domain.com, then linux would be a subdomain of rocks, which is a subdomain of the which is a subdomain of house wich is a subdomain of 'domain' which is technically a subdomain of .com, or the top level domain. :)