Answer Description

Private Clouds offer cloud-like automations and features while still ensuring a complete separation of data and hardware at a physical layer. This gives companies with strict security requirements some of the benefits of a public or hybrid cloud and is a strategy often used by security companies, FINTEC and Government contractors. Public and Hybrid clouds are still used by these types of companies too, but only where security requirements allow for shared infrastructure and "virtual private clouds".

Wikipedia

Cloud computing is the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each of which is a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a pay-as-you-go model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users.