Important details about multi-hosted domains.
Multi-hosted domains function just like any other domain from the visitor's/browser's point of view. If you have a multi-hosted domain "multihosted.com" and your visitor types "www.multihosted.com" into the browser, the browser's address bar will show "http://www.multihosted.com" and not "http://www.maindomain.com/multihosted". If your visitor navigates to another page, the browser will accordingly show "http://www.multihosted.com/anotherpage.html", just like it should.
Multi-hosted domains are not the same as multiple domain parking (pointing multiple domains to the front page of your main domain).
All multi-hosted domain names share the same IP address, control panel, disk space, data transfer, MySQL databases and other resources provided in your main account.
Multi-hosted domains do not have their own POP email accounts. However, each multi-hosted domain comes with a catch-all address that automatically forwards all incoming email to your main domain's POP account.
Multi-hosted domains, unlike your main account domain, cannot have their own subdomains (subdomain.multihosted.com) or SSL certificates.
Multi-hosted domains have their own CGI-BIN.