What is Virtualization?
Virtualization is emulating a physical thing using software. In computer science, virtualization usually refers to using software to emulate a complete computer.
Virtualization was first used by IBM® in the sixties on mainframes, though it only became practical to use with PCs about ten years ago. Its use has exploded since that time and now it's a proven, stable technology with many vendors and options.
Software testing and development are often the first departments to adopt virtualization because they know they can use virtualization software to create and test a wide variety of scenarios in safe, contained environments that accurately emulate the operation of physical servers and client PCs.
What is a Virtual Machine?
A virtual machine (VM) is a software implementation of a physical computer that runs an operating system and executes applications just like a real machine. Virtualization lets you run multiple applications and operating systems independently on a single computer.
The virtual machine has its own software-based CPU, memory, storage and network interface. In other words, the virtual machine emulates a complete computer inside your computer.
Shhh, Don't Give Away the Secret
Operating systems and applications that run on a virtual machine can't tell the difference between the virtual machine and a physical computer. They believe they are on a distinct, separate computer. The virtual computer "thinks" it's a real computer and it looks like a real computer to other computers on the network.
Virtualization is a Dream Come True
You can run multiple virtual machines on one host computer, each with different operating systems, applications, data and settings. For example, you could use virtualization software to create different virtual machines and run Mac® OS X and Windows® 7 on the same physical Linux® server, or run Linux on your Windows PC. It's a dream come true for testers and developers who need to use multiple configurations to test software.
Virtualization is software-based and doesn't require any special hardware. You can run it on any Windows, Mac, Linux or Unix® computer that meets basic requirements.
Check out our Testing and Virtualization FAQ for more answers to your questions