Subdomain is a subdivision on your main domain that you can use for linking or pointing to categories in your website. For example: If you want to create a section for blog in your website then you can create a subdomain blog.yourdomain.com. In this example your main domain is “yourdomain.com” and your subdomain is “blog.yourdomain.com”. Other example of subdomains are mail.google.com, whether.yahoo.com etc.
You can use your subdomain for redirecting it to your different website. Or you can also create sections/category in your website with different subdomains.
To create subdomain from your cPanel you need to follow the following steps:
1) Login to your cPanel.
2) Scroll down to Domains section in your cPanel and click on “Domains” icon.
3) Enter your subdomain name under the “Domain” field and select Just use “test.primarydomain.com”. (primarydomain.com should be your actual domain name.)
If you want to create a subdomain on an addon domain, then enter test.addondomain. (addondomain should be your actual domain name). You need to specify the addon domain name folder after /public_html/ field.
Leave all fields as they are auto completed.
Uncheck “Share document root (/home/username/public_html) with” if it is selected.
4) After that click on the “Submit” button.