Cloud Deployment Models:
IaaS: In the Infrastructure as a Service (IaaS) model, the consumer can "provision" and is able to "deploy and run," but they still do not "manage or control" the underlying cloud infrastructure.
PaaS: In the Platform as a Service (PaaS) model, the consumer has the ability to create applications and host them.
SaaS: In the Software as a Service (SaaS) model, the consumer has the ability to use applications provided by the cloud provider over the Internet.
SecaaS: Security as a Service (SecaaS) offers a way for enterprises to access security services that are robust, scalable and cost effective. SECaaS is a subscription-based business model intended to be more cost effective than smaller individuals/corporations.
Different cloud models are explained below:
Private cloud: The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.
Community cloud: The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g. mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.
Public cloud: The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Hybrid cloud: The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but that are bound together by standardized or proprietary technology enabling data and application portability.