Anatomy of a domain name

Diagram showing the structure of a domain name for a well known site.

The domain name: an essential part of an Internet address

A well formed Internet address has four significant parts. Shown in the diagram running from left to right. 

  1. The extension designates a country, in the form of a two letter code, or a generic business domain: .com .org .net .edu .info .mobi etc. 
  2. The name, often referred to as the domain name, however this is an excessive simplification. It is a name chosen to identify and understand the content of an associated website. The choice of name should adhere to a set of specific rules. 
  3. The sub-domain is a way to zone different sections of a site. Used for specific purposes. 
  4. The prefix indicates the nature of the communication with the domain that is established by the user. http is the prefix that corresponds to the web.