At some point in the labyrinthine discussion of cloud computing, some troublemaker said, “Oh, virtualization and cloud are the same thing” and set off a maelstrom of misunderstanding and confusion about the two.
While it's true that the cloud without virtualization is difficult to imagine, they are not one in the same.
Like the old song “The Blues Had a Baby and They Called It Rock and Roll”, we might say that “Virtualization had a Baby and They Called It The Cloud.”
Like rock n' roll subsumed the blues, so has the cloud subsumed virtualization.
While we can have a virtualized computing environment without the cloud, we can’t have the cloud without virtualization (or at least not without a lot of contorted and expensive work-arounds).
Technology versus Services
Virtualization technology was invented by IBM in the mid-sixties and has since become an industry-standard feature in the data center.
Virtualization software manipulates the server so it can run several different computing environments - multiple operating systems and multiple applications - each in their own partitioned compartment as virtual machines.
This maximizes server capacity and delivers the best possible bang-per-server-buck.
Cloud computing refers to the service – not the technology – that results from the ability to virtualize computing environments.
Although businesses have been maximizing server capacities through virtualization for years, it wasn’t until these virtualized computing environments could be delivered over the Internet that cloud computing became widespread.
"Virtualization is a foundational element of cloud computing and helps deliver on the value of cloud computing," Mike Adams, director of product marketing at VMware. "Cloud computing is the delivery of shared computing resources, software or data — as a service and on-demand through the Internet."
Organizations may leverage cloud services for applications or other services, like storage, that are hosted on the cloud provider’s servers and accessed on a web browser.
The Official Definition of the Cloud
Some of the confusion results from the similarity between a virtualized computing environment and a private cloud, where apps and services may be accessed over the network versus over the Internet.
According to The National Institute of Science and Technology (NIST), a true cloud must have the following five characteristics that a highly virtualized environment may not.
On-demand self-service — Users automatically provision computing capabilities as needed without service provider interaction
Broad network access — Capabilities are accessed through heterogeneous platforms (e.g., mobile phones, tablets, laptops, and workstations)
Resource pooling — The provider’s resources (storage, processing, memory, and network bandwidth) are pooled, dynamically assigned, and reassigned according to consumer demand
Rapid elasticity — Capabilities can be scaled rapidly outward and inward to commensurate with demand
Measured service — Resource usage can be monitored, controlled, and reported, which provides transparency for both the provider and consumer of the utilized service
Virtualized systems and private clouds may look and behave identically to the end-user, but in the datacenter, there are unique differences for each that are ultimately driven by the business requirements of the organization.
"While cloud computing and virtualization each have their own benefits, they are not competing approaches," Mike Adams said. "We view cloud computing as an evolution of virtualization. Customers that virtualize their hardware servers may adopt cloud computing over time for increased self-service, scale, service delivery levels and agility."