BlackRockMT

Hello Community, I am very new to WHMCS and have been trying to watch as many tutorials on youtube as possible. With that being said the architecture of using this product still is a bit confusing for me. I understand you install WHMCS a host server, but when the application comes to actually provisioning servers for hosting (In my case I would like to look at hosting VoIP like Ventrillo etc). When the client purchases a package from me.. is the software allocating space and provisioning a server for the client on the same server I am hosting WHMCS or does a person configure it to provision servers on a different allocation of resources I have rented? Is this done by the base WHMCS solution or are other addons like TCAdmin required for this? As you can tell, I have some wires to uncross and some understanding to gain here.. if anyone can point me to a architecture diagram of a server host service I would greatly appreciate it.