Cloud Delivery and Deployment Models

Three common Cloud Delivery Models are - Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).

IaaS is primarily where a cloud provider provides compute, storage, networking, hardware and operating systems IT resources, thereby giving the cloud consumer a high level of control and responsibility compared to other models. Amazon AWS is a IaaS provider.

PaaS is predefined "ready-to-use" environment such as package of an application server, database platform giving less control to the cloud consumer but a higher level of freedom to spend more time on the actual business logic, sparing the administrative and maintenance tasks. Google App Engine is an example of PaaS.

SaaS is where the cloud provider provides the software package to the consumer as a product. Many SaaS products are available in the market. Gmail is an example of SaaS.

Different combinations of these delivery models are also possible based on consumer's requirements.

Cloud Deployment Models - Again there are three common deployment models - Public Cloud, Private Cloud and Hybrid Cloud. As the name explains, public cloud is publicly available, private cloud is within a data center and hybrid cloud is a combination of public and private cloud (mostly via a Virtual Private Network (VPN) access).