Public cloud:
In Public cloud the computing infrastructure is hosted
by the cloud vendor at the vendor’s premises. The customer has no visibility and
control over where the computing infrastructure is hosted. The computing
infrastructure is shared between any organizations (sharing the infrastructure).
Private cloud:
The computing infrastructure is dedicated to a
particular organization and not shared with other organizations. Some experts
consider that private clouds are not real examples of cloud computing. Private
clouds are more expensive and more secure when compared to public clouds.
Private clouds are of two types:
- On-premise private clouds and externally
hosted private clouds.
- Externally hosted private clouds are also exclusively
used by one organization, but are hosted by a third party specializing in cloud
infrastructure. Externally hosted private clouds are cheaper than On-premise
private clouds.
Hybrid cloud
Organizations may host critical applications on private
clouds and applications with relatively less security concerns on the public
cloud. The usage of both private and public clouds together is called hybrid
cloud. A related term is Cloud Bursting. In Cloud bursting organization use
their own computing infrastructure for normal usage, but access the cloud for
high/peak load requirements. This ensures that a sudden increase in computing
requirement is handled gracefully.
