DNS are hierarchical.
The structure of a domains servers is up to the manager of the domain.
Each server must know about all of the servers below it in the hierarchy.
A server must also know a root server to ask when it doesnt know the name.
There are two basic types of requests that can be sent to a DNS.
A server has different types of entries:
- Address entries relate a name to address.
- Abbreviations - host names without the domain name.
- Mail eXchange entries relate a mail address to IP address. This is why you can send email to a name that you cant use for the web or ftp, such as @ncat.edu
Further information on Domain Name Servers can be found at http://www.win2000mag.com/Articles/Index.cfm?ArticleID=8666