Let's say you're an executive at a large corporation. Your particular responsibilities include making sure that all of your employees have the right hardware and software they need to do their jobs. Buying computers for everyone aren't enough you also have to purchase software or software licenses to give employees the tools they require. Whenever you have a new hire, you have to buy more software or make sure your current software license allows another user. It's so stressful that you find it difficult to go to sleep on your huge pile of money every night.

            Soon, there may be an alternative for executives like you. Instead of installing a suite of software for each computer, you'd only have to load one application. That application would allow workers to log into a Web based service which hosts all the programs the user would need for his or her job. Remote machines owned by another company would run everything from e-mail to word processing to complex data analysis programs. It's called cloud computing, and it could change the entire Computer industry

            In a cloud computing system, there's a significant workload shift. Local computers no longer have to do all the heavy lifting when it comes to running applications. The network of computers that make up the cloud handles them instead. Hardware and software demands on the user's side decrease. The only thing the user's computer needs to be able to run is the cloud computing system's interface software, which can be as simple as a Web browser, and the cloud's network takes care of the rest.

            Any discussion of cloud computing typically begins with virtualization Virtualization is using computer resources to imitate other computer resources or whole computers. It separates resources and services from the underlying physical delivery environment.


Virtualization has three characteristics that make it ideal for cloud computing:

  • Partitioning: In virtualization, many applications and operating systems (OSes) are supported in a single physical system by partitioning (separating) the available resources.
  • Isolation: Each virtual machine is isolated from its host physical system and other virtualized machines. Because of this isolation, if one virtual instance crashes, it doesn't affect the other virtual machines. In addition, data isn't shared between one virtual container and another.
  • Encapsulation: A virtual machine can be represented (and even stored) as a single file, so you can identify it easily based on the service it provides. In essence, the encapsulated process could be a business service. This encapsulated virtual

Machine can be presented to an application as a complete entity. Therefore, encapsulation can protect each application so that it doesn't interfere with another application

Applications of virtualization

Virtualization can be applied broadly to just about everything that you could imagine:

  • Memory
  • Networks
  • Storage
  • Hardware
  • Operating systems
  • Applications

What makes virtualization so important for the cloud is that it decouples the software from the hardware. Decoupling means that software is put in a separate container so that it's isolated from operating systems.