A subdomain is a lower level domain. It is
added on the left of the domain name, e.g. subdomain.example.com. You
can create as many subdomains as allowed by the plan. Domains and
subdomains have equal functional capabilities, including web site
management, e-mail service, FTP, dedicated IPs, etc., but subdomains do
not have their own DNS zones and usually cost less.
To create a subdomain, go through the following steps:
1. Select Domain Info link in Domain Settings menu in user's Control Panel.
2. Click Add in the Sub Domains field. You will be asked to enter the subdomain name
3. Enter the new subdomain. It will be displayed in the Subdomain field of the Domain Settings page.