Cloud computing can have different constellations depending on who offers the cloud services. There is the private cloud for company-specific applications, the public cloud and the combination of both as hybrid cloud.
A public cloud is characterized by the fact that the cloud services such as Software-as-a-Service( SaaS), Storage-as-a-Service, Security-as-a-Service (SaaS) or Platform-as-a-Service( PaaS) are offered to the user by different service providers. The cloud services provided in the public cloud can be used by multiple companies and multiple users within a company.
The user has access to all resources such as the available computing power, storage media and the application programs and can thus reduce the investment in hardware and software and outsource their own data center to the service provider's cloud. The costs incurred are billed according to the services actually provided.