A subdomain is a separate part of your website. Your domain name is the address you registered when you first set up website hosting. A subdomain is then simply anything you place before the first (dot) in the web address. The most common subdomain in use is www, although you can create other subdomains, like news in the example below.
Subdomains are most commonly used when you wish to create a clearly separate part of your website for a specific purpose. For example, Wikipedia use en.wikipedia.org to clearly indicate the English language area of their large website, and then use different subdomains (for example, de.wikipedia.org) for other languages.
Within the Domain Name System, each sub-domain is effectively a completely separate area of your website. It is not a webpage.
Adding a subdomain
To add a subdomain you need login to your control panel and select Hosted Domains from the Domains section.
You will see a list of the hosted domains on your account. To add a new subdomain click the Add New Subdomain button.
You can now enter the details for your new subdomain. Enter what you would like to the subdomain to be called in the Subdomain name field. Whatever you add here will be appended to your main domain name.
If you wish to add web hosting and/or mail services select them using the dropdown boxes. Please note that any resources consumed (e.g. mailboxes or webspace) will be taken from your subscription's resource limits.
Click Next >> and then Finish to confirm and create your new subdomain.
Managing web hosting and mail on a subdomain
Web hosting (e.g. uploading files) and mail is managed on your subdomain through your control panel in the same way as your default domain. Your subdomain will appear alongside it throughout your control panel, allowing you to click into it as necessary to manage it.
When creating certain services (for example mailboxes) you will be presented with a dropdown box allowing you to select whether you wish for it to be created on your main domain or on one of the subdomains.
For example, in the image below we are creating a new mailbox, and have selected to use a subdomain that we have created. People sending email to this mailbox will have to include the subdomain along with the rest of the domain name.
Deleting a subdomain
To delete a subdomain, click on Hosted Domains from the home page of your control panel and then click the subdomain you wish to remove. From here click Delete.