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.