(Domain Name Resolver) - The only real way of connecting to other sites on the internet is to use IP Addresses. Since these numbers are hard for us to remember, domain addresses were invented. A DNR simply takes a domain address, and converts it into it's corresponding IP Address. (i.e. The domain address for this site is WWW.ARCD.COM, but it's IP address is 22.214.171.124. Whenever you enter WWW.ARCD.COM into a program, it gets automatically converted, by the DNR, to 126.96.36.199).
Domain Name Registration. Before you can use a custom domain name for your company, you must first register your name. You may access www.internic.net for a list of certified domain name registrars.
a piece of software living in a Mac's System Folder that helps "resolve" domain names into machine-comprehensible form; you will not know this item exists until something goes wrong with it, in which case you will get the an error message referring to "Domain Name Reslover" (yes, with the picturesque typo there).