Allow me.
VPM is Virtual Private Network... a protocol that allows you to tunnel through the internet from a home or other office to a computer or network at a remote location as though your computer were local to the server.
VM is Virtual Machine... the ability of a computer to run "alien" code (say WindowsXP on a OS X Mac or vice verse) natively in a window of the hosting OS.
The closest to transparent I have ever seen this was the VM ability of the Amiga (680X0) to run Apple Mac (OS 7 & 8, also 680X0) in an emulation window in AmigaOS... and it actually ran faster on the Amiga than the equivalent Mac OS did on a similarly clocked Mac by about 4 or 5 percent.
A truely VM ability would have the software for the host OS and the guest OSes running as fast as they would on native stand alone machines.
Swordman, Good.