The public cloud or public cloud is freely available to everyone over the Internet. The services are provided by an external company. The three largest public cloud providers include Amazon Web Services (AWS), Microsoft Azure and Google Cloud Platform. Customers can take advantage of services such as computing power, infrastructure, storage space, applications and much more from the various providers. The choice of available services is constantly increasing. Among the biggest advantages of the public cloud are low costs, as services are usually billed based on usage, personnel costs are reduced, as operation and maintenance of IT resources become obsolete, and there are no investment costs for server hardware. Furthermore, it offers high scalability and a wide range of available services. It can be set up particularly quickly to meet requirements. If more storage space than originally planned is required, the organization can easily add additional storage.
The Private Cloud makes its cloud computing resources available exclusively to organizations. Unlike the public cloud, it is not accessible to the general public. The private cloud can, for example, be located in a company’s local data center or be hosted by third parties from certain cloud services. It provides a high level of control and security due to private servers and is therefore often used by financial institutions, government agencies or other medium to large organizations with business-critical operations.
One of the advantages of using the private cloud is its adaptability, as the organization can customize its cloud environment to meet specific business needs. Computer, storage and network capacities are adapted to the internal needs of the organization and are not subject to the restrictions of the public cloud. On the other hand, the private cloud offers separate control and security, as this form of cloud computing does not have to be shared with other users.
Disadvantages could, however, represent higher costs, as the private cloud is the most expensive of the cloud types. The use of a private cloud results in comparable personnel, administration and maintenance costs as those of operating conventional data centres. A cost reduction as with the use of a public cloud is not so easily possible. In addition, using a private cloud involves a considerable amount of administrative work, since the internal IT department of the organization has to bear the responsibility and effort of managing the private cloud. External solutions from third-party providers are usually more cost-intensive than using a public cloud.
The two forms of cloud computing differ in a number of significant respects: The services of the public cloud are available to everyone: Although the individual users here also act independently of each other, they all use the same pool of resources. The private cloud grants only authorized users access to the cloud services. The resources are therefore not shared by several users. Furthermore, computer, storage and network capacities in a private cloud can be adapted to the individual needs of the organization. A public cloud cannot usually be adapted so precisely to the individual customer – compared to the private cloud.
Nevertheless, the public cloud also offers some decisive advantages:
The so-called hybrid cloud combines the advantages of both the private and public clouds together in one cloud model. Some of the organization’s data is located in a public cloud and others in a private cloud. Thus, the hybrid cloud offers a comparably high level of flexibility and the often lower costs of the public cloud, but also meets the increased security and data protection needs in organisations, as certain services can only be used internally, as in a private cloud. Organizations therefore benefit from cost savings, maintain their flexibility and are able to store sensitive data securely in the internal area. In the Hybrid Cloud, users can switch between cloud types at any time without being affected by them while working.