Virtualization It's our new way to manage Operating Systems (OS) in a running environment or testing environment.
benefits of using virtualization are many like, Low cost of hardware e.g. instead of purchasing 4 separated hardware for servers we can purchace only ONE and make it run these 4.
One more major advantage is the disaster recovery you can restore your OS in minutes full OS and the running services or application in few minutes.
Plus more other advantages like green IT (Using low power resources), Less maintenance headache ..etc.
As a tester or Systems Administrator you will need from time to time to test OS, applications and so on by using this technology you are saving alot of your time and money.
I'll demonstrate how to create a virtual machine using VirtualBox v2.0.6 it's Open Source you can download it from here It can run on any OS (Linux, MAC, Windows).
See the Video ....