Cloud Computing Cloud Services

Cloud Services

Platform-as-a-service (PaaS) -Provision H/W, OS, Framework, Database
Software-as-a-service (SaaS) - Provision H/W, OS, Special purpose S/W
Infrastructure-as-a-service (IaaS) - Provision H/W and organization has control over OS
Storage-as-a-service (SaaS) - Provision of DB-like services, metered like - per gigabyte/month
Desktop-as-a-service (DaaS) - Provision of a Desktop environment within a browser

PaaS stands for the platform as a service.
PaaS provides a computing platform with a programming language execution environment.
PaaS provides a development and deployment platform for running applications in the cloud.
PaaS constitute the middleware on top of which applications are built.
Application management is the core functionality of the middleware.
PaaS provides run-time environments for the applications.
PaaS provides

Applications deployment Configuring application components
Provisioning and configuring supporting technologies
For users, PaaS interfaces can be in the form of a Web-based interface or in the form of programming APIs and libraries.

Runtime framework: The runtime framework executes end-user code according to the policies set by the user and the provider.
Abstraction: PaaS offers a way to deploy and manage applications on the cloud rather than virtual machines on top of which the IT infrastructure is built and configured.
Automation: PaaS deploy the applications automatically.
Cloud services: Provide services for the creation, delivery, monitoring management, and reporting of applications.

SaaS stands for software as a service.
Software as a service (SaaS) allows users to connect to and use cloud-based apps over the Internet.
SaaS is the service with which end users interact directly.
It provides a means to free users from complex hardware and software management.
In SaaS customers do not need to purchase the software and required a license.
They simply access the application website, enter their credentials and billing details, and can instantly use the application.
Customer can customize their software.
Application is available to the customer on demand.
SaaS can be considered a “one-to-many” software delivery model.
SaaS applications are built as per the user's needs.
From the examples mentioned below, we can find why SaaS is considered one of many models.

The product sold to customers is application access.
The application is centrally managed.
The service delivered is one-to-many.
The service delivered is an integrated solution delivered on the contract, which means provided as promised.

IaaS stands for infrastructure as a service.
Infrastructure as service or IaaS is the basic layer in the cloud computing model.
IaaS offers servers, network devices, load balancers, databases, Web servers, etc.
IaaS delivers customizable infrastructure on demand.
IaaS examples can be categorized into two categories

Some service providers provide both the above categories and some provide only the management layer.
The IaaS management layer also required integration with other IaaS solutions that provide physical infrastructure.
On virtual machines, applications are installed and deployed.
One example of a virtual machine is Oracle VM.
Hardware virtualization includes workload partitioning, application isolation, sandboxing, and hardware tuning.
Instead of purchasing users can access this virtual hardware on pay per use basis.
users can take advantage of the full customization offered by virtualization to deploy their infrastructure in the cloud.
Some virtual machines can be with pre-installed operating systems and other software.
On some virtual machines operating systems and other software can be installed as per use.