Simple Language  Addon domains Means Managing Multiple Domains from a Single Hosting Account.

What do I need to do before creating the addon domain?

First You will require you to correctly configure some DNS settings in Your Domain Control Panel.
Once our nameservers are set up, we can create the addon domain.

You can add a domain on an addon domain in cPanel by completing the following steps:

Step 1: Log into cPanel.

Step 2: In the Domains section, click Addon Domains.

Step 3: In the New Domain Name field, type the domain name you wish to add top of your addon domain.

Note: Once you have entered a domain name, the Subdomain and Document Root fields will automatically populate.

Step 4: Enter a password in the password field. (You won't need to remember this password, so feel free to use the Password Generator button.)

Step 5: Once you are finished filling in the details, Click Add Domain.

Congratulations! You have successfully set up your first add-on domain.