If you are looking forward to having more than one unique website hosted on your account, you can purchase an Addon slot and a domain name from your Web Hosting Service Provider. You need to use cPanel control panel provided with your cPanel hosting package to change the domain, add a domain or park a domain.
Once you have purchased the addon slot and the the domain name, you need to add the domain to the slot from the cPanel > Addon Domains. This will make sure that the addon slot and domain names are added to your account and are ready to use as and when required.
If you are not looking for a separate website but only want a separate domain which will load the same website, then you can park your existing domain names to your primary one. You need to park your domains from your cPanel > Parked Domains. This will make sure that the domain names not required by you are parked in your account and can be used as and when required.
