Cloud computing concept is about providing computing resources (Software, Platform and Infrastructure) as a service over the network. Users can use the services provided by the service provider without taking the trouble of planning, procuring, building, configuring and maintaining the infrastructure.
A real world example: when you travel to another city you don’t buy a plane. You just buy a ticket and pay per use. An airline will take care of maintaining aicrafts and aiprorts and all necessary services. Similarly cloud computing is using computing resources managed by provider and “pay per use” payment. Cloud computing largely divided in two types, Private clouds and Public Cloud.
Private Clouds are cloud services deployed in a datacenter for one client. It may be managed internally or externally by Internal IT or third-party. This gives organization little edge on security but same time because of small scale they won’t able to cost benefits of virtualization but same time
Public Cloud like Microsoft Windows Azure passed the benefit of shared infrastructure and automation in term of low-cost.
Hybrid Cloud is another popular term, a mix of both Private Cloud and Public cloud. In this case organizations host some of the applications on Public Cloud and these applications further internally use Applications hosted on Private Cloud to retrieve the data. This is also an optimize way of using cloud computing.