How does server virtualisation work?
The virtual machine ( VM) is a logical resource that defines a virtualised server, and includes all of the resources typically found in a server or desktop, such as RAM, a CPU, hard disks and network cards. Where the VM differs from a physical system, however, is that it exists as nothing more than a collection of files
The words host and guest are used to distinguish the software that runs on the physical machine from the software that runs on the virtual machine. The software or firmware that creates a virtual machine on the host hardware is called a hypervisor or Virtual Machine Manager.
In hardware or server virtualisation, the host machine is the actual machine where its hardware is used and on which the virtualisation takes place.