What Is Virtualization?

Virtualization enables a physical piece of hardware to run multiple virtual instances of an operating system. In a traditional physical server deployment, every server had its own dedicated physical hardware, with a single operating system, and the server performed a specific function. When it was time to add a new server to the environment, companies purchased a new piece of hardware, installed the operating system, and then configured any applications or services.

With virtualization, the physical hardware with its resources—such as processing power, memory, and disk space—is referred to as the host. Software called a hypervisor enables the physical host’s resources to be shared among many virtual machines. The virtual machine servers are referred to as “guests.” Guests have to share the resources from the physical server. For example, if a host machine has 64GB of RAM, only 64GB of RAM is available to be allocated among the virtual machine guests running on that host.

With virtualization, companies no longer require new physical hardware for every new server because virtual machines can share a common set of physical resources (typically multiple virtualization host servers).