To answer your question:
"if I add a domain, its really a subdomain but accessed by the new url just like the original site?"
When you add a domain to the account, it is considered a second website and is accessed just like any other website. Physically, the files are saved on the server UNDER your primary domain, so, yes, you can consider it a subdomain of the primary domain. However, as I said initially, the website is accessed as a separate website when you type in the URL in an internet browser.
Hope that answers your question!
2014-07-28 5:01 pm EST