Gartner, Inc. defines a hybrid cloud service as a cloud computing service that is composed of some combination of private, public and community cloud services, from different service providers. A hybrid cloud service crosses isolation and provider boundaries so that it can't be simply put in one category of private, public, or community cloud service. It allows one to extend either the capacity or the capability of a cloud service, by aggregation, integration or customization with another cloud service. Varied use cases for hybrid cloud composition exist. For example, an organization may store sensitive client data in house on a bunch of servers, but interconnect that to a BI application hosted on a public cloud.

Another example of hybrid cloud is one where IT organizations use public cloud resources to meet temporary capacity needs that cannot be met by the private cloud. This capability enables hybrid clouds to employ cloud bursting for scaling across clouds. A primary advantage of cloud bursting and a hybrid cloud model is that an organization only pays for extra compute resources when they are needed.

Cloud computing as the next generation of computing provides the following benefits:

• Managed IT infrastructure and services as commodity services developed on a large-scale resource pool beyond standalone processors, storage, business applications and development platforms.
• Billing or charging is based on actual consumption and “pay-as-you-go” economics, even for shorter contracts.A faster path to virtual desktop deployment.
• Scalability that caters to unforeseen business requirements in a timely manner.
• The ability to add or remove capacity in real-time on the basis of changing business needs.
• Easy and user-friendly access, such as web-based interfaces, for the administration of your services and monitoring usage patterns.