Just because some terms are commonly used doesn't mean there's no confusion surrounding them. So here are definitions of three such terms. Public cloud computing: Infrastructure -- including computers, storage and operating systems -- and applications offered as services on a subscription basis. For example, Amazon.com Inc.'s Elastic Compute Cloud service offers virtualized servers that users rent to run workloads over the internet. The public cloud provider controls where the workloads execute. Private cloud computing: Infrastructure -- including computers, storage and operating systems -- and applications offered as virtualized services to users. The organization owns and controls its infrastructure and applications, which run behind a corporate firewall. The IT organization manages the virtualization tools, policies and workload deployment. Finally, hybrid cloud computing is a mix of public and private virtualized infrastructure and applications where workloads shift in and out of each sphere, in an automated way or not, based on policies.
