Theres no single, perfect cloud architecture or infrastructure. All clouds require operating systemslike Linuxbut the cloud infrastructure can include a variety of bare-metal, virtualization, or container software that abstract, pool, and share scalable resources across a network. This is why clouds are best defined by what they do rather than what theyre made of. Youve created a cloud if youve set up an IT system that:

You can build a private cloud on your own or use prepackaged cloud infrastructure like OpenStack, and there are thousands of cloud service providers all over the world. Here are some of the most popular:

Creating a hybrid cloud strategy requires some degree of workload portability, orchestration, and management. Application programming interfaces (APIs) and virtual private networks (VPNs) have been the standard ways to create these connections. Many of the major cloud providers even give customers a preconfigured VPN as part of their subscription packages:

Another way of creating a hybrid cloud is to simply run the same operating system in every environment and build containerplatform-based, cloud-native apps that are managed by a universal orchestration engine like Kubernetes. The operating system abstracts all the hardware while the management platform abstracts all the apps. So you deploy almost any app in almost any environment without retooling the app, retraining people, splitting management, or sacrificing security.

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Understanding cloud computing - Red Hat