A public cloud refers to the services of a service provider that are accessible to the general public via the internet. Neither the hardware nor the services offered belong to the customers. Typical examples are the allocation of data storage space, the provision of webmail services or joint work on documents in a web browser. To make things more clear: Dropbox, Gmail and Office 365 are typical examples of public cloud services. These are especially popular with private individuals. In contrast to the private cloud, in this case, all the customers of the cloud provider share the resources that it provides.
Formulated in more abstract terms, this cloud model can also be described as a pool of virtual resources. The respective service provider combines hardware with virtualization technologies which it makes available to its customers via an interface.
This virtualization is powerful, and is an efficient way of adapting to workloads with unexpected fluctuations in demand. The large and well-known providers for cloud solutions of this kind include Amazon AWS, Microsoft Azure and Google Cloud, etc. A few years ago, public clouds were only offered off-premises. The times are changing – and public clouds can now be provided on-premises. The big cloud providers have recognized the requirement of many companies and established it in their business models.
Attributes of the public cloud
- Shared services: All the customers share the computing power of the hardware of the provider of the public cloud
- Web-based access: The different services of the public cloud are usually available via a web browser
- Pay-on-demand/pay-per-use: use-based pricing
- Customers only pay for the IT resources that they have actually used
- Reliability: The big players in the cloud business have several years of experience, IT resources and personnel for ensuring a high degree of availability and reliability
Disadvantages of this cloud model
- Limited flexibility: The services offered through a public cloud cannot be adapted easily in order to fulfil the requirements of a customer. As clouds of this type are always a resource that is shared with many other users, this is simply not possible.
- Compliance/security problems: An influence on the way in which the cloud provider saves corporate (!) data, or whether they respond regularly and quickly to security problems with the use of software updates, is beyond the control of the customer. In terms of compliance and the legal requirements, the public cloud is not an easy topic either. For companies in highly regulated industries (e.g. finance, healthcare, etc.) in particular, the requirements of the business customer may conflict with the public cloud model.
Learn more about this cloud model on the following page.