Public Cloud Model
Public Cloud allows systems and services to be easily accessible to general public. The IT giants such as Google, Amazon and Microsoft offer cloud services via Internet. The Public Cloud Model is shown in the diagram below.
There are many benefits of deploying cloud as public cloud model. The following diagram shows some of those benefits:
Since public cloud shares same resources with large number of customers it turns out inexpensive.
The public cloud employs large number of resources from different locations. If any of the resources fails, public cloud can employ another one.
The public cloud can smoothly integrate with private cloud, which gives customers a flexible approach.
Public cloud services are delivered through Internet, ensuring location independence.
Utility Style Costing
Public cloud is also based on pay-per-use model and resources are accessible whenever customer needs them.
Cloud resources are made available on demand from a pool of resources, i.e., they can be scaled up or down according the requirement.
Here are some disadvantages of public cloud model:
In public cloud model, data is hosted off-site and resources are shared publicly, therefore does not ensure higher level of security.
It is comparatively less customizable than private cloud.