Creating A Subdomain in CPanel
Navigate to your cPannel Login.
Once arrived, find the Domain Manager Panel.
Click Subdomains, and set the subdomain name. In this case, I am creating a development subdomain where I can make changes to my site that I can share with friends without taking my site offline.
If you receive a success message, then a new directory has been created in your file structure. The directory is accessible by navigating to [subdomain].[domain].[extension]!
You can see that in your FTP client or File Manager.