Define Public Cloud

It is built over Internet and can be accessed by any user who has pad for the service. Public clouds are owned by service providers and are accessible through a subscription.
Public cloud providers are:
- Google App Engine(GAE)
- Amazon Web services(AWS)
- Microsoft Azure
- IBM Blue cloud
- Saleforce.com
They were commercial providers that offers a publicly accessible remote interface for creating and managing VM instances withing their proprietary infrastructure.
A Public cloud delivers a selected set of business processes. The application and infrastructure services are offered on a flexible price per use basis