What is a domain name?

A domain name (such as wiredpen.com) is a human-readable name that maps to an IP (internet protocol) address. Every device that is connected to the internet has a unique IP address. Some are permanent addresses; this is what we want for domain names. Some are temporary or transient; that’s what UW assigns to our personal devices (phones, Kindles, etc) that connect to the network.

The domain name is part of a Uniform Resource Locator (URL) used to access web sites, for example:

• URL: http://www.kegill.com/index.html
• Top-level domain name: com
  
• Second-level domain name: kegill.com
• Host name: www.kegill.com

Domain names are organized right to left, with general descriptors to the right, and specific descriptors to the left. The far right portion of every domain name is the suffix that indicates its top level domain (TLD). Prominent TLDs are  com, info, net, edu and org, as well as country code top-level domains (ccTLDs) like .us or .za (Wikipedia links). The Internet Corporation for Assigned Names and Numbers (ICANN) manages the top-level development and architecture of the Internet domain name space.

The mid- or second-level domains are in the middle. The machine name, which may be “www” or something else (365.kegill.com), is to the far left. The levels are separated by periods that we pronounce as “dot”. When we look to the right of the TLD (the part of the address beyond the “/”) we are looking at web server directories and files.

Because the Internet is based on IP addresses, we need a Domain Name System (DNS) server that will translate domain names (human readable) into IP addresses (machine readable).

Domain name registrars are accredited by ICANN and make money by charging an annual fee for their services. Many are either in partnership with or owned by the same web hosting company.

Check your IP address!