Domain Name Basics

Although domain names are now just as common as telephone numbers very few people actually understand how they are constructed and what purpose they serve.

With telephone numbers the actual structure wasn't really important for the end user as they didn't control or issue that number but instead it was assigned to them by a telephone company.

However domain names are fundamentally different as the end user has a choice of name and also is responsible for creating that name.

There is an issuing authority involved with the registering of the domain name but the authority only controls a part of the name.

To understand that you need to become familiar with the basic domain name structure.

The domain name structure is a hierarchical structure the top of the structure is a dot (.).

 Underneath the dot are what are known as the top level domains (TLDs) which are strictly controlled (e.g. com, net, UK) by international authorities.

Underneath the top level domains are second level domains like IBM, Microsoft and Juice, in our example below.

domain name structure-2

This second level name is typically the name of an organisation and control over this name is given to that organisation, which can then use it as it sees fit.

This is the part of the domain name you must choose yourself and you can use any name you want provided that:

  1. It isn't already registered.
  2. It uses valid characters. a-z, 0-9 and the hyphen -
  3. Valid Length 2-63 characters, including the tld.

 Lets take for example this domain name oeupdates.com.

 Once I had registered this domain name I was free to use it as I wanted.

I could use it :

  • As a domain name for a website (e.g. www.oeupdates.com)
  • As a basis for email addresses someone@oeupdates.com
  • Divide it into sub domains blog.oeupdates.com
  • Use the subdomains as websites
  • Use the subdomains as basis for email addresses someone@blog.oeupdates.com

You can see that choosing and registering a domain name is the starting point for an Internet presence whether it is for a website or for email addresses or both.