Cloud Service Models

Service Models
- SaaS (Software-as-a-Service):
  - Provides on-demand online access to specific software applications or suites without the need for local installation.
  - Reduces hardware and OS limitations, making it accessible to a wide range of users.
- PaaS (Platform-as-a-Service):
  - Offers a complete computing platform and software solution stack as a virtual or cloud-based service.
  - Eliminates the need for purchasing and maintaining high-end hardware and software locally.
  - Customers supply application code, which is executed on the vendor’s infrastructure.
- IaaS (Infrastructure-as-a-Service):
  - Extends PaaS by offering complete outsourcing options, including on-demand operating solutions, utility computing services, dynamic scaling, virtualization services, and more.
  - Supports administrative task automation, policy implementation, and managed/filtered Internet connectivity.
Deployment Models
- Private Cloud:
  - Cloud-based assets are dedicated to a single organization.
  - Organizations can create and host private clouds using their own resources.
- Community Cloud:
  - Shared cloud-based assets between two or more organizations.
  - Maintenance responsibilities are distributed based on who is hosting the assets and the service models involved.
- Public Cloud:
  - Cloud assets available for any consumer to rent or lease, hosted by an external Cloud Service Provider (CSP).
  - Service Level Agreements (SLAs) ensure that CSPs provide services at an acceptable level to the organization.
- Hybrid Cloud:
  - A combination of public and private cloud models, allowing for a mix of both types of services.

Additional Notes

The parent organization is still responsible for patching the OS of virtual hosts in these models.
CaaS (Containers-as-a-Service): Note that CaaS is not a recognized term in the original cloud service model taxonomy.

Understanding these models is critical for choosing the right cloud solutions and deployment strategies to meet organizational needs, especially in terms of scalability, control, and cost management.