Glossary

Para-virtualization is a virtualized server technique that emulates real or fictional hardware for a modified guest OS. The para-virtualized server is a modified guest OS running on top of the hypervisor (virtual machine monitor). The guest OS has been modified so that the guest OS makes system calls directly to the hypervisor (not executing I/O instructions directly to the machine), and the hypervisor simulates the machine feedback (and negotiates with the actual machine).
The main difference between a virtual machine and para-virtualization is that the guest OS on a virtual machine is an unmodified off-the-shelf product, but the guest OS in para-virtualization is modified to work more directly with the hypervisor.

Physical to physical migration (P2P) defines the process of moving a complete OS environment, and the installed applications, from one physical server to another physical server. This is done by cloning drives and putting the cloned drive into a new server, using server virtualization as an intermediate process, or by using application virtualization to easily control the movement of applications from one physical environment to another.

Physical to virtual migration (P2V) defines the process of capturing and migrating a complete OS environment, and the applications installed on it from a physical server to a virtual environment.