Public Cloud: In a public cloud, the cloud resources (like servers and storage) are owned and operated by a third-party cloud service provider and delivered over the Internet.
Private Cloud: In a private cloud, the services and infrastructure are always maintained on a private network and the hardware and software are dedicated solely to your organization. A private can be hosted in the on premise or with a third-party provider. In this way, a private cloud can make it easier for an organization to customize its resources to meet specific IT requirements.
Hybrid cloud: Hybrid clouds combines on-premises infrastructure, or private clouds, with public clouds so organizations can reap the advantages of both. In a hybrid cloud, data and applications can move between private and public clouds for greater flexibility and more deployment options. For instance, you can use the public cloud for high-volume, lower-security needs such as web-based email, and the private cloud (or other on-premises infrastructure) for sensitive, business-critical operations like financial reporting. In a hybrid cloud, applications or resources can run in the private cloud until there is a spike in demand (such as seasonal event like online shopping, month end consolidations, or tax filing), at which point the organization can move to the public cloud to tap into additional computing resources.