I'm sure you've noticed that some website URLs require the presence or absence of "www" in front of them in order to work. This is a DNS thing! If a site doesn't have a "www" DNS entry...then the URL won't work in your browser.
I remember the first time I ever saw a tech use NSLOOKUP - I asked him "How do you learn about tools like this?" One answer is to use a study package that teaches you through video and hands-on activities. :-)
Server 2008 introduces some new DNS features:
-> Background zone loading. I’ve never seen a heavily loaded DNS server, but presumably this helps a busy server start answering client requests right away, rather than waiting for the whole entire zone to be loaded first.
-> GlobalNames zone – this is cool, because you can now tell DNS about simple NetBIOS names (i.e. machines that are not in a domain), just like in WINS. Sweet!
-> Conditional forwarding can now be replicated in Active Directory (presumably in the past it was staying put on the individual DNS server).
-> Global Query Block List – this helps you keep hackers from registering an unwelcome computer name (e.g. a fake web proxy) on your DNS servers.
-> ...and RODC, LLMNR, DNSSEC, domain controller search, and IPv6/AAAA record support. I did not look into these.