DNS stands for Domain Name Server.
What is DNS?
When you enter a URL into the address window of your browser, the DOMAIN NAME is sent to a DOMAIN NAME SERVER which "looks up" the IP ADDRESS associated with that DOMAIN, then routes your browser's request to the SERVER associated with that IP. This is the computer equivalent of calling 411, speaking the name of the person you're trying to call, then being connected
The Domain Name Server associated with your website is recorded and propagated throughout the world by your REGISTRAR. At one time, Network Solutions was the only registrar in the U.S. and domain names registrations costs $35/year with a two-year minimum term. Today there are scores of registrars and annual registrations can be accomplished for under $10.
RDN Associates handles all of your website details: initial registration of your DOMAIN NAME, DOMAIN NAME RENWALS, changing REGISTRARS (when required), DNS changes, as well as FORWARDING and ALIASING your DOMAIN NAMES.