cPanel offers three ways to add a domain and they do quite different things.
Addon domain
A completely separate website on the same hosting account, with its own folder and its own content. Use this when you want a second site. It gets its own certificate and its own email addresses.
Subdomain
A section of an existing domain – shop.example.com, blog.example.com – with its own folder. Use this for a distinct part of the same site.
Parked domain (alias)
A second name pointing at your existing site. example.net showing the same content as example.com. Use this for alternative spellings, other endings, and old names you have replaced.
Choosing correctly
The mistake is adding a domain as an addon when you meant to park it. You then have two separate empty sites and one of them shows nothing, or worse, duplicate content that search engines see as two competing copies.
If you want the same site on two names, park it and then set a permanent redirect from the alias to your main name, so there is one canonical address.
All of them need DNS pointing here
Adding a domain in cPanel does not make it work on its own. The domain must also point at this server, either by using our nameservers or by an A record. Until it does, cPanel will accept it but nothing will load – and no certificate will be issued.
