Under the hood: Domain names explained

We all know about web addresses right? But what do we know about domain names?

This is the first in a series of under the hood articles for those who’d like a more in depth knowledge and understanding of how the Internet works on a more technical level.

This article seeks to demystify the world of domain names.

I’m not going to attempt to cover all the aspects of domain management in this article but by the end of it you should be more familiar with the terminology, concepts and mechanics of domain names.

Let’s start of by nailing some terminology. Domain names are essentially unique but human readable names that form the basis web and email addresses. They pull together web pages, applications and email for a given domain.

The anatomy of a domain name

A domain name has two main parts

  • Top Level Domain (TLD)
  • Label

and it takes the following form label.tld

There are general open top level domains such as .COM, .NET and .ORG and there are country code top level domains like .UK, .DE or .AU.

The general open TLDs are available for anyone to use although historically and originally they were devised for very specific purposes for example .com is short for commercial and was originally the preserve of commercial organisations, .net is network and was originally used to describe a network, where .org was initially intended for use solely by not for profit organisations.

A full list of worldwide TLDs can be found in this extensive Wikipedia entry: http://en.wikipedia.org/wiki/List_of_Internet_top-level_domains

The label is the more meaningful aspect that reflects you or your business. For example our label for this site is jujuhq.

Case insensitive

Domain names are case insensitive, however you enter the domain name in a browser it will always resolve to the lowercase version of the domain for example GooGLe.Com will always go to google.com.

Often people publish domain names with camel case to add clarity when the domain consists of more than one word, for example consider the technical forum Experts Exchange whose domain name is expertsexchange.com on first inspection and out of context that could just as easily be ExpertSexChange when in fact it’s ExpertsExchange.


Domain names are registered and leased for a year or more at a time via companies who act as registrars.

Organisations exist to oversee the business of domain registration and there are different bodies associated with different top level domains (TLD). The body for general TLDs is the Internet Corporation for Assigned Names and Numbers (ICANN).

In the UK the authorising body is Nominet and throughout the rest of Europe it’s the Council of European National top Level Domain Registries (CENTR)

Each of these bodies controls the registration and supply of domain names either directly or through their registered members.

When you choose to register a domain name the company acting as a registrar will either be a member of one of these organisations or a reseller for one who is.

For example in the UK I use UK2.Net for my registrations and they are registered with Nominet for the .UK country code TLD but for .COM they resell through an ICANN registered company called eNom Inc.

Once you have registered your domain name then you can use it for the duration of the lease at the end of which you will be given the opportunity to renew or let it lapse and then it returns back onto the open market.

What happens next

So now you have your domain name what do you do with it? you will need to attach your domain to email and web hosting services for it to be any use to you.

Your domain name is just that, a registered name in a directory. It will come with a generic parking page so that if you were to enter it into your web browser you would be served a page that informs you that the domain is registered and it will generally be covered with advertising for the registrar giving visitors the opportunity to register their own names.

If you don’t already have a hosting solution with web and email services then you will need to select one.

Most registrar companies offer bundled services of domain name with an email service and web hosting together.

Decoupling the registration from the hosting service

Personally I choose just to register my domain names with one company and then use a third party hosting service for email and webspace.

I do this for two reasons. Firstly so that I don’t have all my eggs in one basket and secondly because
a lot of the bundles, whilst on the face of it appear good value for money, often come with performance issues because the hosting aspect will be on a shared server.

Shared servers are not a bad thing but there is a tendency of a lot of the bundle offering companies to oversell, which means that you will be on a server with a few hundred or even thousand of other sites which can cause performance issues.

I’ll cover hosting solutions how traffic is routed around the internet to find your site in another article.

Can I have more than one domain name?

Of course, you can register as many as you want and many people do. It’s advisable from a brand protection perspective to reserve all the open general TLDs for your label along with the relevant country code TLD so  in the UK you should reserve the .co.uk, the .com, the .net and the .org. There are others but those would be the minimum.

You can also another domain name that describes a product or service or location for example:

  • jujuhq.com
  • jujuhq.co.uk
  • jujudigital.com
  • jujudigital.co.uk
  • webdevelopmentsuffolk.co.uk

All of the above domains point to this website. The primary domain is jujuhq.com and all others serve as aliases or parked domains. They all lead to the same place. It’s important from an SEO perspective to ensure that each domain also redirects to the same location as well to avoid potential penalisation from the search engines for duplication.

The how to for redirection is beyond the scope of this article, so long as you are aware of it you can discuss it with your web professional.

If your business domain name doesn’t say what you do then It’s actually a good idea to have the domain that’s likely to be most attractive to the search engines as the primary domain name and your business name based domain name as a secondary alias. You can still publish your business based domain name on all your marketing material and use that as the domain to manage email from but a domain name with your keywords will perform better for you than an obscure business name.


For every new domain name you want you will have to pay to register and then subsequently renew but what if you just want a separate domain for say a related micro site or separate shop or speciality section. Well for these situations there are what’s known as sub domains and you can have as many of these as your hosting solution permits. normally the only limitation is space.

a subdomain consists of a prefix label so it might look like this:


Giving you a completely separate document root on your server which means that it the file space is completely separate. This gives you a completely fresh hosting environment this can attract its own traffic and be managed independently of your main site.


You should now have more of an understanding of domain names, the different types of domain, their basic anatomy, who’s responsible for issuing and governance surrounding them and how they’re registered and how they can be used to good effect.

In other articles I will write more about the mechanics of managing name server entries, that help route the traffic around the Internet and how to mange redirections.

I hope this has been helpful for you. Please let me know your thoughts in the comments below.

Alex Adams

Alex has been designing, developing and managing software projects since 1998. He is a multidisciplinary developer and has worked with a number of languages, technologies and frameworks. When he's not developing, he's a busy husband and dad who finds a bit of time to train for triathlon events.

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