When you think of virtualization, think of it as a way of consolidating servers. Virtualization is the process of separating the software layer of a server from its hardware layer. A new layer is placed between the two to act as a go-between this is known as the hypervisor.
Companies used to have multiple servers with each server operating system on its own piece of server hardware. In virtualization the server, including the operating system, applications, patches, and data, is encapsulated into a single image or virtual server.
A single physical server, called the host, can run four or five of these images or virtual servers simultaneously, saving the company money on the following:
Purchase of hardware, as less servers are needed
Consolidate management of the machines
Reduced energy consumption, as there are less servers
Much more efficient use of resources, as the new machine(s) will be able to share those resources
Failure in one machine will not lead to the failure of others
Most computers operate using as little as 4 percent to 7 percent of their resources. There are many visualization companies in the market; the two that we have mentioned in this chapter are Microsoft Hyper-V and VMware.