Well, what I think you are asking is how to park, or add a domain to your x10 account. You also seem to want to know what an addon and parked domain is/are. Well, first, an addon domain is a domain that is used for your website. For example, x10hosting.com is addedon to the server. A parked domain is a domain that is temporarily stored on a server until the final website is ready. Now, how to park/add a domain is really simple. First, you need to configure your domain to point to x10's NameServers. This can be done in your registrar's DNS control area. Next, you need to login to cpanel and click addon domain(s). Finally, enter the information required in that form and it will work in a few hours. Or, to park a domain, do everything above, excluding the cpanel part, instead go to parked domain(s), then yet again fill in the info. If that didn't cover it, then post again.