What is a Domain Extension?

What does .com or .net actually mean, and how do you choose the right extension for your website? We take look at the the most commonly used extensions, the differences between them, and how to choose the right one for your business.

One of the most common questions our clients ask is “should I get a .com, or a .net …. what’s the difference?!”So, here’s a quick guide to this part of your domain name – the domain extension.

Quick Background to Domains

The Domain Name System (DNS) was invented in 1983. This system allowed a name to be attached to the numeric IP address, meaning that instead of a long string of numbers like, a specific place on the internet could be identified by a name, like ‘baloogi.com’ – much easier to remember!

In 1984, the Internet Assigned Numbers Authority (IANA) established the first six domain extensions:

.com | .edu | .gov | .mil | .org | .net

Shortly afterwards, the first two-character country code extensions (like .uk and .us) were established.

It wasn’t until much later in 1998, with the creation of Internet Corporation for Assigned Names and Numbers (ICANN) that any new domain extensions (except country code extensions) came into use.

We now have hundreds of domain extensions, and the list is still growing: .aero, .biz, .coop, .info, .museum, .name, .cat, .jobs, .mobi, .tel, .travel, .tv, .cc, .eu and .asia to name just a few.

The Most Common Domain Extensions

.com (commercial)

The most popular extension by far, and one of the original top-level domains, .com has come to be synonymous with the internet. Originally intended for use by purely commercial entities, .com is unrestricted, and can therefore be registered for anything, by anyone.

.org (organization)

Another original top-level domain, .org is traditionally associated with non-profit organizations, charities and the open source movement. It can also be registered by anyone, for anything.

.net (network)

Originally intended for network infrastructure use, the .net extension has evolved into a popular alternative to .com. Also unrestricted, meaning that anyone can register the extension for any purpose.
.info (information). An unrestricted extension intended for informative or ‘resource’ type websites, introduced to try to relieve pressure on the overcrowded .com extension.

.gov (government)

Used by government entities in the United States. The U.S. is the only country that has a government-specific top-level domain, due to the origins of the Internet as a US Federal Government-sponsored research network. Other countries typically use a second-level domain for this purpose, e.g., .gov.uk for the United Kingdom or .gov.au for Australia. These domains are restricted to government entities only.

.biz (business)

Derived from the phonetic spelling if the first syllable of ‘business’, .biz is intended for small businesses. It was created due to the demand for good domain names available in the .com top-level domain, and to provide an alternative to businesses whose preferred .com domain name which had already been registered by another.

.mobi (mobile)

Introduced in 2006, the .mobi extension is intended to be used for sites designed to be viewed on mobile devices such as smart phones.

co.uk, .au, .us (country specific)

Country specific extensions are generally top level domains reserved for use within a specific country, sovereign state or territory.

Which Extension Should I Choose?

As a general rule of thumb, most experts will advise that you choose a country specific extension (such as .co.uk or com.au) if your desired market lies solely within your country. If your business operates (or has the potential to operate) internationally, you should probably choose a .com or a .net domain extension, if your desired domain name is available. There is a general consensus that search engines like Yahoo and Google generally rank .com domains more highly in search results. Likewise, they will rank local domain extensions (ie., country specific) more highly in local searches.

Of course, if you are a non-profit making organization or charity, a .org makes the most sense.

If your desired domain name is not available (ie someone else has already registered it), you’d be better advised to consider changing the actual domain name, than registering a more obscure extension. For example, at the time of writing, the domain ‘cheapestcarpets.co.uk’ was not available. The less desirable ‘cheapestcarpets.biz’ was available. However, if we ‘tweaked’ the domain name slightly, to cheapest-carpets.co.uk (note the added hyphen), we find the .co.uk and the .com extensions both available. We can take our pick – even register both!

Unless you have a very good reason for doing otherwise, choose a memorable, well-known extension. Think about it – would you be more likely to remember cheapestcarpets.com or cheapestcarpets.me.uk? Which would look better printed on your business cards?