Before I go into virtualization, let's talk a bit about what defines a computer. A computer is a mesh of hardware and software that performs useful tasks through running programs such as creating text and spreadsheet files, playing movies, and surfing the Internet. In order to run, these specific programs need work on top of another larger program called an operating system or OS for short. This "master program" has two sides: one that interacts with the programs like Word and Photoshop, the other side interacts with hardware. Therefore, when you tell Word to print out on paper that novel you just wrote, Word does not tell the printer directly to print. Rather, it tells the OS to tell the printer to print. There are many OSes out there for many different types of hardware. Microsoft Windows is the most famous of these because it can be found in over 90% of computer hardware out there. The OS is the most important part of a computer's software collective. Malicious programmers, such as those who write computer viruses, write their programs to attack the OS. Their "thinking" is that if they can bring down the OS, then all the programs running on top of it will collapse as well. Keep this in mind because I will bring this issue up again when we talk about virtualization.

In simplest terms, virtualization is the process in which multiple OSes can run on a single physical computer at the same time. We are all familiar with the simultaneous running of multiple programs on our computers, like running Word and Internet Explorer in separate windows. To capture the focus and use a program, you simply click on the designated window. If your computer is powerful enough and has plenty of memory, you can run a dozen programs at the same time. However, no matter how many programs you have running on your computer at the same time, they all run on top of a single OS. Therefore, all of your programs are affected if your OS is compromised by a computer virus.

Now, what if we have multiple OSes running on the same physical machine at the same time? Well, you can choose to run some programs on one copy of an OS, and some on another. This allows you to run vulnerable programs, like Outlook (a popular email program), on a separate copy of Windows so that if a virus infects this copy of Windows through Outlook, the damage is done locally. Another copy of Windows that is running concurrently is completely safe and will continue to work just fine running its own collection of programs. This is only one of several uses of virtual machines, and you can see the potential benefits already.

Another popular use of virtual machines is to run different versions or even different types of OSes on the same physical machine. Let's say you have a program that is only compatible with Windows 95 and another program that is only compatible with Windows XP. Instead of buying two physical machines, just buy one that is reasonably powerful and run Windows 95 and XP on it at the same time. This way, you can run both of your programs. Money saved and free space for that vase of roses you always wanted on your desk.

Another great use of virtual machines is mobility. Let's say you have a database program that you have been using for your business for years. Things may work fine now, but you know that in the future, the computer will break down and you will need to reinstall the program and put back the data. With simpler programs like Word, this is not a big deal, but with a complex database program, the data can be difficult to move to a new machine. With virtual machines, the entire virtual OS wherein the database program runs is stored in a single folder. Therefore, you can move this folder to another physical computer and start up the database program instantly without the need to rebuilt it from scratch. Think of the time and money you can save!

There are many other powerful uses of virtual machines. I have barely scratched the surface. Only a live demonstration of this technology can fully show you the technology's potentials. Setting up virtual machines is a bit of a pain, but using them is a breeze. At Techcollective, we have setup virtual machines for at least half a dozen customers, and so far all of them love their benefits. Not only have we saved them money in the long run, but we also reduced the complexity in managing their information, given the consolidating nature of virtualization.