1 - "as a Service" Flashcards
Another excellent way to make sense of the many cloud technologies today is to break them down by the “as a Service” category they fall under. The concept of “as a Service” means that customers “subscribe” to IT resources as needed.
This is currently the most popular cloud model. Here the customers access a provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser, or a program’s interface. Note that in this model, the customer does not manage or control the underlying cloud infrastructure, with the possible exception of limited user-specific application configuration settings.
Software as a Service (Saas)
This model provides a cloud infrastructure to the customer. This permits the customer to deploy onto the cloud infrastructure consumer-created or acquired applications developed for the cloud. The provider ensures the required programming languages, libraries, services, and tools are available for the customer. Typically, this is done on a pay-per-use or charge-per-use basis. Note that in this case, a cloud infrastructure is the collection of hardware and software that enables the five essential characteristics of cloud computing. The cloud infrastructure can be viewed as containing both a physical layer and an abstraction layer. The physical layer consists of the hardware resources necessary to support the cloud services being provided, and typically includes server, storage, and network components. The abstraction layer consists of the software deployed across the physical layer, which manifests the essential cloud characteristics. Conceptually the abstraction layer sits above the physical layer. Notice also that the customer does not manage or control the underlying cloud infrastructure, including the network, servers, operating systems, and storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
Platform as a Service (PaaS)
Allows the customer to provision processing, storage, networks, and other fundamental computing resources. The customer is then able to deploy and run arbitrary software, which can include operating systems and applications. The customer does not manage or control the underlying cloud infrastructure, but has control over operating systems, storage, and deployed applications. The customer might also have limited control of select networking components such as host firewalls.
Infrastructure as a Service (IaaS)
