Subdomains can point to different sections of your website. In order to create a subdomain in your cPanel account, follow the next steps.
Step 1: Log into your cPanel account.
Step 2: In the Domains section, click on the Subdomains icon.
Step 3: Under Create a Subdomain in the Subdomain field you should enter your subdomain name like demo and should you have several domains, select the appropriate domain from the dropdown list.
Step 4: Click on the Create button.