Defining Cloud Deployment Models
Each company chooses a deployment model for a cloud computing solution based on their specific business, operational, and technical requirements. There are four primary cloud deployment models: private cloud, community cloud, public cloud, and hybrid cloud. Here is how each of the deployment models are defined:
The term private cloud has been described as neologisms, but the concept behind it pre-dates the term cloud by 40 years. Even within modern utility industries, hybrid models still exist despite the formation of reasonably well functioning markets and the ability to combine multiple providers.
Some cloud vendors have used this term to describe offerings that emulate cloud computing on private networks. These offerings are able to deliver some benefits of cloud computing and at the same time mitigate some of the shortcomings. In the private cloud, the infrastructure is managed and operated exclusively for one company in order to keep a consistent level of security, privacy, and governance control. It can exist on or off premise, and can be managed by a company or a third party.
A community cloud refers to cloud computing environment shared and managed by several organizations that have similar requirements and are sharing the infrastructure in order to realize some of the benefits of cloud computing.
With the costs spread over fewer users than a public cloud this option is more expensive but may offer a higher level of privacy, security and/or policy compliance. It may be managed by the company or a third party and can exist on or off premise.
Public cloud or multi-tenant cloud, describes cloud computing in the traditional mainstream sense. Resources are dynamically provisioned on a fine-grained, self-service basis over the Internet, via web services, from an off-site third-party provider who shares resources and bills on a fine-grained utility computing basis. The cloud infrastructure is owned by a cloud vendor, and is accessible to the general public or a large industry group.
A hybrid cloud environment consists of multiple clouds (private, community, or public) and is the typical cloud deployment model for most enterprises. By integrating multiple cloud services users may be able to ease the transition to public cloud services while avoiding issues such as PCI compliance.
In this cloud computing deployment model, an organization provides and manages some resources in-house and has others provided externally. The main benefit of the hybrid cloud is that it provides the scalability and low costs of a public cloud without exposing mission-critical applications and data to third-party.