Virtual systems are created out of
physical systems. Given a computer
system with a certain set of resources,
you can set aside portions of those
resources to create a virtual machine.
A virtual machine has all the attributes
and characteristics of a physical system
but is strictly software that emulates a
physical machine.
A system/hardware virtual machine has
its own address space in memory,
, processor resource allocation, and
device I/O using its own virtual device
drivers.
Some virtual machines are designed to
run only a single application or process
and are referred to as process virtual
machines.
Virtual machines provide the capability
of running multiple machine instances,
each with their own operating system.
A hypervisor or virtual machine monitor
(VMM) is computer software, firmware
or hardware that creates and runs virtual