Cloud computing explained

Here I would like to explain  cloud computing simply for newbies.

Cloud computing is the next stage in the Internet's evolution, providing the means through which everything — from computing power to computing infrastructure, applications, business processes to personal collaboration — can be delivered to you as a service wherever and whenever you need.
The “cloud” in cloud computing can be defined as the set of hardware, networks, storage, services, and interfaces that combine to deliver aspects of computing as a service. Cloud services include the delivery of software, infrastructure, and storage over the Internet (either as separate components or a complete platform) based on user demand. (See Cloud Computing Models for the lowdown on the way clouds are used.)
Cloud computing has four essential characteristics: elasticity and the ability to scale up and down, self-service provisioning and automatic deprovisioning, application programming interfaces (APIs), billing and metering of service usage in a pay-as-you-go model. (Cloud Computing Characteristics discusses these elements in detail.) This flexibility is what is attracting individuals and businesses to move to the cloud.
The world of the cloud has lots of participants:

• The end user who doesn’t have to know anything about the underlying technology.
• Business management who needs to take responsibility for the governance of data or services living in a cloud. Cloud service providers must provide a predictable and guaranteed service level and security to all their constituents. (Find out what providers have to consider in Cloud Computing Issues.)
• The cloud service provider who is responsible for IT assets and maintenance.
  
  
  
  
   
  
  
   
  
  
  
  
  
  
  Cloud computing is offered in different forms: public clouds, private clouds, and hybrid clouds, which combine both public and private. (You can get a sense of the differences among these kinds of clouds in Deploying Public, Private, or Hybrids Clouds.)
  Cloud computing can completely change the way companies use technology to service customers, partners, and suppliers. Some businesses, such as Google and Amazon, already have most of their IT resources in the cloud. They have found that it can eliminate many of the complex constraints from the traditional computing environment, including space, time, power, and cost.
  
  
  The goal of cloud computing is to apply traditional supercomputing, or high-performance computing power, normally used by military and research facilities, to perform tens of trillions of computations per second, in consumer-oriented applications such as financial portfolios, to deliver personalized information, to provide data storage or to power large, immersive computer games.
  To do this, cloud computing uses networks of large groups of servers typically running low-cost consumer PC technology with specialized connections to spread data-processing chores across them. This shared IT infrastructure contains large pools of systems that are linked together. Often, virtualization techniques are used to maximize the power of cloud computing.
  
  
   See a simple video
  
  
  
  
  
  
  
  
  
  
  

  Cloud Computing in the Data Center and for Small Business

  Cloud computing has started to obtain mass appeal in corporate data centers as it enables the data center to operate like the Internet through the process of  enabling computing resources to be accessed and shared as virtual resources in a secure and scalable manner.
  For a small and medium size business (SMB), the benefits of cloud computing is currently driving adoption. In the SMB sector there is often a lack of time and financial resources to purchase, deploy and maintain an infrastructure (e.g. the software, server and storage).
  In cloud computing, small businesses can access these resources and expand or shrink services as business needs change. The common pay-as-you-go subscription model is designed to let SMBs easily add or remove services and you typically will only pay for what you do use.