Knowledgebase

A subdomain is a domain using your main domain and a prefix name. As an example, let's say our main domain is example.com. We want to create a domain for our support department and direct visitors to a separate area on our web site. Our subdomain would use "support" as the prefix and "example.com" as the main domain. The example of putting these two together are shown below:

EXAMPLE: support.example.com

Consider a subdomain a url for any area on your web site. You can create the prefix as any name you want based on your own personal preferences.

Creating A Subdomain

Steps

To create a sub domain, perform the following steps:

1. Click Create a New Domain. A new interface will appear.
2. Enter a fully qualified domain name in the Domain text box.To create a subdomain, enter a new name followed by a period (.) and then the website’s domain. For example, enter subdomain.example.com to create a subdomain of example.com.
3. Optionally, you can specify the directory where you want the files for the domain to exist (the domain’s document root). To create this directory, deselect the Share document root with “example.com” checkbox, where example.com represents your main domain. You cannot use the following directories
   • The account’s home directory itself (/)
   • Directories outside of the account’s home directory (./ and ../)
   • .cpanel
   • .trash
   • etc
   • mail
   • ssl
   • tmp
   • logs
   • .cphorde
   • .spamassassin
   • .htpasswds
   • var
   • cgi-bin
   • .ssh
   • perl5
4. To automatically redirect the new domain’s visitors from the insecure version of the website to the secure version, set the Force HTTPS Redirect toggle to On.
5. Click Submit or click Submit and Create Another Domain.

cPanel reference: https://docs.cpanel.net/cpanel/domains/domains/