website.qxd  4/9/2003  11:52 AM  Page 25

DOMAIN NAMING

What Is a Domain Name?

Your Domain Name is your address on the web. Just as people use your phone number to call you

on the phone, your Domain Name allows people to access your site on the web. Clever, simple, or

easy to remember Domain Names are most desirable as they can play a large part in attracting

visitors to your site. Most Domain Names end with  .com  (such as microsoft.com), but other

extensions such as  .net  and  .org  are also available. In addition, Domains can be used with

your  email  accounts,  allowing  you  to  send  and  receive  email  with  addresses  such  as

 support@yourcompany.com  

Internet Domain Namespace

The root (the topmost level) of the Internet domain namespace is managed by an Internet name

registration  authority,  which  delegates  administrative  responsibility  for  portions  of  the  domain

namespace to organisations that connect to the Internet. 

Beneath the root DNS domain lie the top-level domains that are assigned by organisation and by

country, and are managed by the Internet name registration authority. These domain names follow

the International Standards Organization (ISO) 3166. Each organisation is assigned authority for

a portion of the domain namespace and is responsible for administering, subdividing, and naming

the DNS domains and computers within that portion of the namespace. 

Subdividing is an important concept in DNS. Creating subdivisions of the domain namespace and

private  TCP/IP  network  DNS  domains  supports  new  growth  on  the  Internet  and  the  ability  to

continually  expand  name  and  administrative  groupings.  Generally,  subdivisions  are  based  on

departmental or geographic divisions. There are three types of top-level domains: 

a

Organisational domains. These are named by using a 3-character code that indicates

the primary function or activity of the organisations contained within the DNS domain.

a

Geographical domains. These are named by using the 2-character country/region codes

established by the International Standards Organization (ISO) 3166. 

a

Reverse  domains. This  is  a  special  domain,  named  in-addr.arpa,  that  is  used  for  IP

address-to-name  mappings  (referred  to  as  reverse  lookup).  There  is  also  a  special

domain, named IP6.INT, used for IP version 6 reverse lookups. .or information, see R.C

1886. 

Abbreviations are reserved for use by organisations and by countries. The most commonly used

top-level DNS name components for organisations and countries are described in the table below: 

Copyright  NESIS 2002

25