DNS, or Domain Name System, is an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. However, the Internet however, is really based on IP addresses. Every time you use a domain name, a DNS service must translate that name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
For additional information, see the NovellĀ® DNS online documentation.