Hybrid cloud
Hybrid cloud is combinations of private and public clouds. In reality, service providers and companies often need to utilize the best of both worlds, i.e. utilize public cloud elasticity, emerging state of the art technologies and on-demand pay-as-you-go billing models while, at the same time, maintaining part of the applications and data on-premise or in a private cloud, to maintain application compatibility as well as security and privacy compliance. In order to make hybrid clouds a reality, a networking mechanism needs to be introduced by the business, which would interconnect on-premises infrastructure to public cloud infrastructure. To securely connect private and public clouds a Virtual Private Network (VPN) can be utilized, which makes cloud applications appear to be on the same internal network as the enterprise. VPNs can be set up on a per-application basis or for the entire corporate infrastructure.