Anatomy of a URL

by Andy Wibbels

http://andywibbels.com/

A web address has many parts.

Understanding which parts do what can help you better understand how your readers and search engines see

your site.

www.yourdomain.com

Here’s a domain name.

www.yourdomain.com

Let’s break it down into its many parts.

www.yourdomain.com

That thing on the end? That’s called a Top Level Domain.

Common top-level domains

Each country has it’sown top-level domain:

Full list at http://en.wikipedia.org/wiki/Country-code_top-level_domain

www.yourdomain.com

So that’s the top-level domain, the part after the ‘dot’ and before the

‘everything else.’

www.yourdomain.com

Let’s take a look at the part‘between the dots.’

www.yourdomain.com

It doesn’t allow spaces or underscores.

www.yourdomain.comwww.YourDomain.com

www.YOURDOMAIN.com

It is not-case sensitive. All of the above go to the same place.

www.your-domain.com

You can have dashes.

www.yourdomain12.com

Or numbers.

www.yourdomain12.com

Together with the top-level domain. This is what most people mean when

they talk about ‘a domain name.’

www.your-domain12.comwww.your-domain12.netwww.your-domain12.orgwww.your-domain12.au

These are all different domain names, that might be owned by

different people.

www.your-domain.com

So that was the part ‘between the dots.’

www.your-domain.com

Let’s look at the part ‘before the dot.’

www.yourdomain.com

The part before the first dot is called the sub-domain.

www.yourdomain.com

Yes, you’re right. It doesn’t make sense that it is ‘sub’ and is first as you

read it out loud.

www.yourdomain.com

Make peace with that.

www.yourdomain.commail.yourdomain.comblog.yourdomain.comstuff.yourdomain.com

Sub-domains allow you to channel different bits of traffic to different

parts of your company.

www.yourdomain.commail.yourdomain.comblog.yourdomain.comstuff.yourdomain.com

All of these sub-domains are controlled by the same person that

owns the domain name.

www.yourdomain.com

The default is ‘www’for ‘world wide web.’

www.mail.yourdomain.com

A common mistake is adding the ‘www’ if there is already a domain

name.

www.mail.yourdomain.com

That isn’t necessary and may cause weird error messages.

yourdomain.com=

www.yourdomain.com

Depending on how a site is setup, you don’t have to type in the ‘www.’

yourdomain.com≠

www.yourdomain.com

Other times they are different.This small detail may drive you batty when troubleshooting so be vigilant.

www.yourdomain.com

So: sub-domain.

www.yourdomain.com

Domain.

www.yourdomain.com

Top-level domain.

www.yourdomain.com

Usually referred to as one big thing called ‘a domain name.’

http://www.yourdomain.com

So what’s this H-T-T-P business?

http://www.yourdomain.com

There are many ways for you to connect to a website.

http://

The most common used by browser isHypertextTransferProtocol

http://

Hypertext is a nerdy way of saying ‘web site stuff.’

http://

The http:// tells the web server how to respond to the request to view a

particular web page or file.

http://

The colon and 2 forward slashes just make it look fancy.

http://

Yes, the direction of the slashes matters.If they lean to the right – into the direction you’re reading, they are forward slashes.

If they lean to the left – they are backslashes.

http://www.yourdomain.com

Another piece of the puzzle!

http://www.yourdomain.com/stuff

Uh-oh. What’s this?

http://www.yourdomain.com/stuff

This tells the website, I want to see your folder of stuff.

http://www.yourdomain.com/stu_ffhttp://www.yourdomain.com/1 23http://www.yourdomain.com/FuN

This folder on the webserver can be case sensitive and can contain spaces and underscores. It is separate from the

domain name system.

http://www.yourdomain.com/stuff

This part points us to the server. This part tells us what to get once we’re there.

http://www.yourdomain.com/stuff/something/important.pdf

The path to these files can be as long as it needs to be.

This part points us to the server. This part tells us what to get once we’re there.

http://www.yourdomain.com/stuff.xls

This tells the website, I want to see a spreadsheet called stuff.xls.

http://www.yourdomain.com/stuff.htm

This tells the website, I want to see a webpage called stuff.htm.

http://www.yourdomain.com/stuff

If there is no file requested – just the folder – the server may respond with

the ‘index’ of that folder.

http://www.facebook.com/profile.php?id=505504719

Sometimes a URL has variables in it that tell the site what to do. Here is the full URL to my Facebook profile.

The browser talks to Facebook and asks for the profile.php file

the profile.php file is a script and looks for a variable called ‘id’ and that is how it knows what Facebook profile to show.

But at the end of the day, the important thing to remember is this:

www.yourdomain.com

Sub-domain.

www.yourdomain.com

Domain.

www.yourdomain.com

Top-level domain.

www.yourdomain.com

Usually referred to as one big thing called ‘a domain name.’

Thanks!Let’s connect:

http://andywibbels.com/