Domain Name System, or DNS, is the friendly naming system for giving addresses to web servers and web pages. Somewhat like international phone numbers, the DNS gives every server a memorable and easy-to-spell address. Simultaneously, the domain names hide the really technical IP address which most viewers aren’t interested in.
Some example internet domain names:
- customwebsitesetc.com
- nytimes.com
- navy.mil
- harvard.edu
- monster.ca
- japantimes.co.jp
- wikipedia.org
- gamesindustry.biz
- spain.info
- sourceforge.net
HOW DOMAIN NAMES ARE SPELLED
1) Domain names are organized right to left, with general descriptors to the right, and specific descriptors to the left. It is like family surnames to the right, specific person names to the left. These descriptors are called “domains”.
2) The “top level domains” (TLD, or parent domain) is to the far right of a domain. Mid-level domains (children and grandchildren) are in the middle. The machine name, often “www”, is to the far left.
3) Levels of domains are separated by periods (“dots”).
Example 1 above – CustomWebsitesETC is the mid-level domain, .com is the top level domain.
Example 6 above – japantimes is the smaller mid-level domain, .co is the larger mid-level domain and .jp is the top level domain.
Example 9 above – spain is the mid-level domain, .info is the top level domain.
Note: Most American servers use three-letter top level domains (e.g. “.com”, “.edu”). Countries other than the USA commonly use two letters, or combinations of two letters (e.g. “.au”, “.ca”, “.co.jp”).
A DOMAIN NAME IS NOT THE SAME AS URL
To be technically correct, a domain name is commonly part of a larger internet address called a “URL”.
A URL goes into much more detail than a domain name, providing much more information, including the specific page address, folder name, machine name, and protocol language.
Example Uniform Resource Locator pages, with their domain names bolded:
http://horses.about.com/od/basiccare/a/healthcheck.htm
http://www.nytimes.com/2007/07/19/books/19potter.html
http://www.nrl.navy.mil/content.php?P=MISSION
http://www.fas.harvard.edu/~hsdept/chsi.html
http://jobsearch.monster.ca/jobsearch.asp?q=denver&fn=&lid=&re=&cy=CA
A DOMAIN NAME IS NOT THE SAME AS IP ADDRESS
In the end, a domain name is intended to be a friendly and memorable “nickname” only. The true technical address of a web host is its Internet Protocol Address or IP Address (255.255.255.4).