As the cloud paradigm grows in depth and breadth, more readers are approaching the topic for the first time, or from a new perspective.  This blog is a basic review of  cloud deployment models, to help orient newcomers and neophytes.

Most cloud deployments today are either private or public. It is also possible to connect a private cloud and a public cloud to form a hybrid cloud.

A private cloud is for the exclusive use of an organization. Enterprises, universities and government agencies throughout the world are using private clouds. Some have designed, built and now manage their private clouds. Others use a private cloud that was built by and is now managed by a provider, hosted either onsite or at the provider’s datacenter. Because private clouds are for exclusive use, they are usually the option chosen by organizations with concerns about data security and guaranteed performance.

Public clouds are open to anyone with an Internet connection. Because they require no capital investment from their users, they are particularly attractive to companies with limited resources in less regulated environments and for temporary workloads such as development and test environments. Public clouds offer a range of products, from end-user software packages to more basic services such as databases or operating environments.

Public clouds may also offer cloud services such as a disaster recovery for a private cloud, or the ability to “cloudburst” a temporary workload spike from a private cloud to a public cloud. These are examples of a hybrid cloud. These are most feasible when the private and public clouds are built with similar technologies.

Usually people think of a public cloud in terms of a user role, e.g., “Which public cloud should I consider using?” But someone needs to own and manage that public cloud. The company who owns and operates a public cloud is known as a public cloud provider. Oracle Database Cloud Service, Amazon RDS, database.com and Savvis Symphony Database are examples of public cloud database services.

When evaluating deployment models, be aware that you can use any or all of the available options. Some workloads may be best-suited for a private cloud, some for a public or hybrid cloud. And you might deploy multiple private clouds in your organization. If you are going to combine multiple clouds, then you want to make sure that each cloud is based on a consistent technology portfolio and architecture. This simplifies management and gives you the greatest flexibility in moving resources and workloads among your different clouds.

Oracle’s portfolio of cloud products and services enables both deployment models. Oracle can manage either model. Universities, government agencies and companies in all types of business everywhere in the world are using clouds built with the Oracle portfolio. By employing a consistent portfolio, these customers are able to run all of their workloads – from test and development to the most mission-critical -- in a consistent manner: One Enterprise Cloud, powered by Oracle.