Public clouds, private clouds, and hybrid clouds

Here, you will learn about a high-level overview of the different types of cloud computing deployment models. You will learn more details in Chapter 5, Cloud Migration and Hybrid Cloud Architecture Design.

A private cloud, or on-premises, is registered to a single organization that owns and accesses it. Private clouds act as a replicate or extension of the company's existing data center. Often, a public cloud has shared tenancy, which means virtual servers from multiple customers share the same physical server; however, they offer dedicated physical servers to customers if the customer wants it for a license or compliance need. A public cloud such as Amazon Web Services (AWS), Microsoft Azure, or Google Cloud Platform (GCP) creates a massive IT infrastructure, which can be utilized over the internet with a pay-as-you-go model.

A third model is a hybrid cloud, used by large enterprises who are moving their workload from on-premises to a cloud, where they still have a legacy application that cannot move to the cloud directly, or maybe they have a licensed application that needs to stay on-premises, or sometimes due to compliance reasons, they need to secure data on-premises. In such a situation, the hybrid model helps, where the enterprise has to maintain a partial environment on-premises and move other applications to the public cloud. Sometimes an organization moves to test and develop the environment to the public cloud and keep production environments on-premises. A hybrid model can vary depending upon the organization's cloud strategy.