A private cloud platform is a cloud platform that is offered to one customer, and one customer only. By contrast, public cloud platforms serve multiple customers. A private cloud platform is completely walled off from other IT systems serving other customers.
Essentially, private cloud platforms and public cloud platforms provide the same types of services. They both provide offsite data storage, web-delivered applications and all of the functionality that cloud services are known for. They provide scalability, on-demand resources, and the ability to provision machines. However, the big difference is that private cloud services are designed and engineered for single companies.
Along with the definition of private cloud as being provisioned for a single customer, private cloud platforms can also offer the customer more control over their own data. Many of these platforms are administrated by IT staff who are on premises at the client company, not in the offices of the cloud service provider.
Some of the big value propositions for private cloud platforms involve security and data control. Although some public cloud systems may be safe for sensitive data, there is the commonly cited idea that certain kinds of issues could trigger a data breach, where that data resident on public cloud systems is more vulnerable to unauthorized access. IT pros talk about things like “dirty disk” problems, where disk images are not fully cleaned of data before being used for another client company. This type of issue applies to “multitenant” cloud systems where, essentially, the cloud company serves multiple clients with one architecture; that single architecture can be logically provisioned so that each company’s data is separate, but things can still go wrong, while in a private cloud, there is no chance of data cross-contamination.
In addition to private cloud and public cloud setups, companies can use hybrid setups, where elements of public cloud computing and private clouds are incorporated into a full system. A more sophisticated modern philosophy of service allows companies to keep the most sensitive data assets in the private cloud, while moving some resources into the public cloud, which is sometimes called “cloud bursting.” There is a lot of workload analysis involved in figuring out when hybrid systems should keep data in private setups, or migrate it to public cloud.