Virtualization is a technique, which allows to share single physical instance of an application or resource among multiple organizations or tenants (customers). Creating a virtual machine over existing operating system and hardware is referred as Hardware Virtualization. Virtual Machines provide an environment that is logically separated from the underlying hardware.

The machine on which the virtual machine is created is known as host machine and virtual machine is referred as a guest machine. This virtual machine is managed by a software or firmware, which is known as hypervisor.


The hypervisor is a firmware or low level program that acts as a virtual machine.

There are two types of hypervisor:

1. Type 1 Hypervisor

Eg LynxSecure, RTS Hypervisor, Oracle VM, Sun xVM Server, VirtualLogic VLX.


                        Type1 Hypervisor

                             Type 1 Hypervisor

The type1 hypervisor does not have any host operating system because they are installed on a bare system.

2. Type 2 Hypervisor

Type 2 hypervisor is a software interface that emulates the devices with which a system normally interacts.

Eg Containers, KVM, Microsoft Hyper V, VMWare Fusion, Virtual Server 2005 R2, Windows Virtual PC and VMWare workstation 6.0.

                    Type2 Hypervisor

Type 2 Hypervisor