Virtualization is a concept most likely you will be familiar of.
Take an example. Consider PSCX. It’s an emulator, which allows you you to play PS2 games on a PC right? That’s basically virtualization at work. Virtualization is a fancy name for emulation. Virtualization software allows you to virtualize a machine, create a “virtual” PC – you can do anything on the virtual pc as you can do on a normal PC – Install an OS, run applications, compile applications, surf the web, the applications are limit less. So why virtualize you may ask?
Well that depends on what you want to do. If you’re a developer, wanting to test cross-platform applications(ie, applications that will run across multiple OS) virtualization provides you to do so without the hassles of actually installing the required OS.