One of the growing trends in IT in recent years has been the increase in the use of virtualization to reduce the number of physical computers needed in an environment. Virtualization provides the ability to run multiple operating systems on one computer. Virtual operating systems (known as virtual machines or VMs) use a hypervisor to allow multiple virtual operating systems (guests) to run at the same time on a single computer (host). The hypervisor is also known as a virtual machine manager (VMM).
An operating system running as a virtual machine acts just like an operating system installed on a separate computer. You can install programs, access the Internet, print to printers, and do just about everything else that you can do with a physical computer. For example, virtualization allows you the option to test Windows 7, Windows Vista, and Windows XP, and even a Windows Server OS all at the same time. You can create virtual machines (VMs) for each OS, which could include a variety of Windows and Linux based operating systems.
Client-side virtualization, or virtualization on desktop computers, is often used to test operating systems and software applications in a controlled environment. You can install and reinstall operating systems and applications, make configuration changes, and see how those changes will affect the system before actually installing them into a production environment. One of the features of a virtual machine is the ability to take a snapshot of the system, then roll back to that snapshot later on. This is especially useful in a classroom or training environment where systems can be setup a certain way, then allow students to make configuration changes, install various applications, test out different tools, and then roll back to that original image when done. It can also be useful when dealing with viruses, malware, and spyware—to see how those things infect a system in a controlled environment—and the system can be rolled back to a snapshot of the “clean” system. Virtual machines also allow you the opportunity to set up your own training lab environment, with various desktop and server operating systems that can interact with each other, all hosted on the same physical machine.
There are several different software programs that allow you to create and run virtual machines, but two of the most common are VMware Player and VirtualBox. These are free programs that allow you to get started using virtualization on standard desktop or laptop computer systems. You can download and install these applications and begin to create your own personal computer training lab.