A subdomain is part of a domain that comes before the actual domain. So if your actual domain name was yourdomain.com, a subdomain would be subdomain.yourdomain.com. By way of example, sport.bbc.co.uk is a subdomain, as is docs.google.com.
Subdomains are very useful and easy to create with us. In cPanel, you can add them by clicking ‘subdomains’ in the control panel.
You will be asked which folder you want the subdomain to run from. This will be the path where you upload the files to. If you leave it as default it will be something like /public_html/subdomain/
This means you would have to upload your website files to that subdomain. If you are autoinstalling software using Softaculous, do not worry about that
One thing that may suprise you is that www.yourdomain.com is also a subdomain, as is www.google.com. Actually, a www prefix is not at all required, but was built into the initial design of the internet.
However, you will note that the www content does not run from a separate folder (like a new subdomain would). Instead, it is essentially something called a ‘parked domain’. It points to the same content as the non-www does.
If you want to achieve that for whatever reason, go to the cpanel, click ‘parked domains’ and then add the subdomain there. This will then show the same content as on the main website and load the content from public_html.
If you want to set up DNS records for a subdomain (for example to point a third party site like Flickr or Google Apps), then you do not actually need to add a subdomain. You can instead do this by creating a DNS record.
In cPanel click ‘Simple DNS Zone Editor’ and you can add that there.