- I give people (basically, anybody x86 member who wants it) access to x86labs.org's main server
- I don't give people access to x86labs.org:81's forum server
- I give restricted database access to many servers (including my laptop, the forum, the main server, and others that you don't especially need to know about)
Does that clear it up?
In addition, the VMWare server also acts as a firewall. The virtual servers are set up as a DMZ and my actual network is set up as a Trusted LAN. Every incoming connection goes to the DMZ, no incoming connections can ever get to the Trusted LAN. Within the DMZ, I have a decently set up network, with a database server, a couple web servers, and testing servers. If I could run a DNS, I'd have a DNS server in there too. So in addition to everything else, this lets me learn about setting up a network.
In terms of speed, there's no noticeable loss. Every server feels like it's the only one on the box while using it, except when they all boot at the same time. I run ~7 or 8 servers at the same time, and it's rare for one of them to use a significant amount of CPU/RAM more than 1% of the time, so they get along nicely. VMWare is quite good at freeing up resources when a system isn't using them.
Also, I'm not a hosting company, I'm a guy with a properly-configured home network.