by Dave Moorman
According to Wikipedia:
Virtualization is the creation of a virtual (rather than actual) version of something, such as a hardware platform, operating system, a storage device or network resources.
While that is the technical description, it helps to know what virtualization accomplishes:
Virtualization is a key part of any new infrastructure designed today. Virtualization provides more scalability, better use of current hardware resources and much greater manageability. The goal of virtualization is to centralize administrative tasks while improving High Availability (HA) and Disaster Recovery (DR).
If this sounds a little too abstract, it’s easy to understand virtualization by peering into history. In the 1970’s computing power was extremely expensive. Due to the expense, IBM would create mainframe computers that served as a hub so that multiple computers could use the computing resources. This allowed for multiple people to tap into a single computer at the same time.
Virtualization lets you run multiple virtual servers or desktops on a single physical machine (host), sharing the resources of that single server. Basically, you are gaining more scale while using less server hardware. Virtualization works by inserting a thin layer of software directly on the server hardware or host and then loading multiple versions of the operating systems on top of it. This software layer contains a virtual machine monitor which allocates hardware resources dynamically and transparently. Multiple operating systems run concurrently on a single physical server (host) and share hardware resources with each other. You can safely run several operating systems and applications at the same time on a single server (host), with each having access to the resources it needs when it needs them.
The rise of the PC allowed everyone to have enough computing power to accomplish the tasks they needed at work and at home. Today, technology has circled back to its roots. Business owners realized that they were using troves of resources to maintain their IT department while the majority of their server hardware was using only 5% to 15%of the systems capacity on average. In the 70’s computers had to be physically attached to the mainframe in order to tap into its resources. Today, the Internet allows computing and storage to be centralized while distributing their resources in milliseconds across the globe. You no longer need your own servers or mainframes to have a world class IT infrastructure, you just need virtualization. The cloud is built on this virtualization technology. Welcome to the Cloud!