What is cloud computing and how it works
Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network (Internet).. These cloud services is divided into three different categories. Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). The name comes from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams.
A cloud service has three distinct characteristics that differentiate it from traditional hosting. A user can have as much or as little of a service as they want at any given time; and the service is fully managed by the provider “the consumer need a personal computer and Internet access”. Significant innovations in virtualization and distributed computing, as well as improved access to high speed Internet and a weak economy, have accelerated interest in cloud computing.
A cloud can be private or public. A public cloud sells services to anyone on the Internet. (Currently, Amazon Web Services is the largest public cloud provider.) A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of customers. When a service provider uses public cloud resources to create their private cloud, the result is called a virtual private cloud. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
- Infrastructure as a Service (IaaS)
Infrastructure as a Service is a provision model in which an organization outsources the equipment used to support operations, including storage, hardware, servers and networking components. The service provider owns the equipment and is responsible for housing, running and maintaining it. The client typically pays on a per-use basis. Like Amazon Web Services provides virtual server instance API to start, stop, access and configure their virtual servers and storage.
- Platform as a Service
Platform as a Service allows users to create software applications using tools supplied by the provisioning hosting capabilities. PaaS services can consist of pre-configured features that customers can subscribe to choose their features that meet their requirements while discarding those that do not. Consequently, packages can vary from offering simple point-and-click frameworks.
PaaS offerings may also include facilities for application design, application development, testing and deployment as well as services such as team collaboration, web service integration and marshalling, database integration, security, scalability, storage, persistence, state management, application versioning, application instrumentation and developer community facilitation.
- software as a service
In the software as a service cloud model, the vendor supplies the hardware infrastructure, the software product and interacts with the user through a front end portal. SaaS is a very broad market. Services can be anything from Web based email to inventory control and database processing. Because the service provider hosts both the application and the data, the end user is free to use the service from anywhere.