Think of it as another space of your domain.

Let's say that you have a simple website with Gandi's Simple Hosting service, and publish it at http://www.example.com. In this case, your site is hosted on the www subdomain.

But what if you want to have a blog too? One that does not interfere with the website? Easy: simply set up your blog on a different subdomain, such as "blog". Visitors can then access your blog at http://blog.example.com and your website still at http://www.example.com.

Do you want to publish your photo album that you made with Sitemaker too? No problem: put it on another subdomain, such as "photos". Your album will be visible at http://photos.example.com, and your other sites will not be affected in the slightest.

Anything else? Perhaps a wiki that you host on a VPS? Again, just add another subdomain….

All that you need to to is to add a line in your DNS zone file.

The purpose of the entry is to tell the nameserver where to find the location of your website.

Let's say you want to "point" www.example.com to a Gandi Simple Hosting server. To do this, you'll need to add an entry in your DNS zone file like this (use the expert interface, it's easier):

www 10800 IN CNAME gpaas1.dc0.gandi.net.

(Don't forget the dot at the end of the CNAME entry or it will not work!!!)

And perhaps you have a mobile phone website hosted by Wix and you need a "m" subdomain, then you just add a line like:

m 10800 IN A 216.139.213.144 

etc.

Your host will tell you whether or not you need to add an IP address or a subdomain. If it is an IP address that you need to use, then you'll create an A record. If you are given a CNAME record (like web.me.com. etc.) then you need to make a CNAME record.

The changes to the zone file can only be done with the company that manages your DNS.

If you are using Gandi's DNS, you can see how to add your CNAME or A records in order to create your subdomain, visit one of the below pages:

• How to add or change an A record
• How to add or change a CNAME record