Domain Name System

The Domain Name System, or DNS, is a naming system for anything connected to the internet. Its primary use is to allow humans to use meaningful domain names, such as www.google.com, in place of computer-readable IP address, such as 74.125.225.50. In addition, these names are not case sensitive making it unnecessary to memorize capital letters.

Organization

Syntax

A domain name is made up of several parts called labels, seperated by periods. The right most label in a domain name is associated with the top level domain. Subsequent labels to the left are additional sub-domains of the top level domain[1].

For instance, in "ctools.umich.edu", "edu" is a top level domain to which "umich" is a subdomain, with "ctools" being a subdomain of that.

Top Level Domains

Every domain name ends with a top level domain. These are labels such as ".edu" ".org" and most commonly ".com".

There were seven original generic top level domains as well as 2-character country designation codes. The original and common seven are: ".gov" for government websites,".mil" for military websites,".com" for commerce websites,".edu" for education-associated websites,".org" for organization's websites,".net" for networks, and ".int" for international websites.[2]

Second Level Domains

A domain name can have a limitless number of sub-domains. As in the example "ctools.umich.edu", "umich" is a subdomain of "edu" where "ctools" is a subdomain of "umich." The preceeding element in a domain name, such as "www" indicates what the host server function is. For instance "mail.google.com" provides a specific function that is different from "www.google.com."

Ethical Issues

One common problem associated with the structure of domain names is confusion that can accompany it due to a domain name being all lowercase and containing no spaces. There are many examples where this has made otherwise unassuming domain names deter customers from visiting a website, such as "goredfoxes.com" for "Go Red Foxes", "therapistfinder.com" for Therapist Finder, and "molestationnursery.com" for "Mole Station Nursery". Similarly, typos of commonly visited sites are sometimes registered to get get some of the traffic intended for the legitimate site. For instance, "leagueoflegends.co" redirects a user to a Spanish webpage with adult content, as opposed to "leagueoflegends.com" which would bring the user to Riot Games' popular League of Legends game.[3]