The private cloud is defined as computing services offered either over the Internet or a private internal network and only to select users instead of the general public. Also called an internal or corporate cloud, private cloud computing gives businesses many of the benefits of a public cloud - including self-service, scalability, and elasticity - with the additional control and customization available from dedicated resources over a computing infrastructure hosted on-premises. In addition, private clouds deliver a higher level of security and privacy through both company firewalls and internal hosting to ensure operations and sensitive data are not accessible to third-party providers. One drawback is that the company’s IT department is held responsible for the cost and accountability of managing the private cloud. So private clouds require the same staffing, management, and maintenance expenses as traditional datacenter ownership.
Two models for cloud services can be delivered in a private cloud. The first is infrastructure as a service (IaaS) that allows a company to use infrastructure resources such as compute, network, and storage as a service. The second is platform as a service (PaaS) that lets a company deliver everything from simple cloud-based applications to sophisticated-enabled enterprise applications. Private clouds can also be combined with public clouds to create a hybrid cloud, allowing the business to take advantage of cloud bursting to free up more space and scale computing services to the public cloud when computing demand increases.