Free Sub-Domains The number of Sub-Domains included in your web hosting plan. Subdomains A subdomain is an extension of your domain that helps you to manage your site. You can have additional hostnames such as "products.yourdomain.com" that people can use to access specialized areas of your web site. If you cancel or delete hosting a given domain the subdomains for that domain will also cease to work as you cannot have a subdomain without having the parent domain active.