Many IT people used works on their PC or Laptops required of two or more OS like windows OS and Linux OS installed in their machine this was a problem for these IT people because it was uncomfortable in order to switch from one OS to another OS by shutting down it first before startup another OS.
Nowadays IT people prefer to use virtual machine to boot up another OS on top of the main OS that you use. Virtual Machine is a software implementation of a machine that executes programs like physical machine. In contrast, a process in virtual machine is designed to run a single program which means that it supports a single process. These are some advantages and disadvantages of using this virtual machine that I have experienced where multiple OS environments can co-exist on the same computer in isolation from each other, when I do learning about hacking I do not need to worry when the OS that I installed on the Virtual machine attacked by virus because it is isolated to my main OS. The disadvantage of using VM is that a virtual machine is less efficient than areal machine when it access the hardware indirectly and it tend to slower the process to execute a program when you do not have a powerful machine to run multiple OS of 2 on the same computer.
One of the famous virtual machine is VMWare where you can get it from http://www.vmware.com/ to download the latest version of VMWare. By using the VMWare you can install many OS that you want to use in order to learn another OS when you run your main OS or even to learn about networking like hacking or manage network for different OS.
