Pilvandmetöötl

Pilvandmetöötl, often referred to as cloud computing, is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (for example, networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This model promotes availability and is composed of five essential characteristics, three service-description models, and four deployment-description models.

The essential characteristics of cloud computing include on-demand self-service, broad network access, resource pooling, rapid elasticity or expansion, and measured service. On-demand self-service allows consumers to provision computing capabilities as needed automatically without requiring human interaction with each service provider. Broad network access means capabilities are available over the network and accessed through standard mechanisms. Resource pooling serves multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. Rapid elasticity allows capabilities to be elastically provisioned and released to scale rapidly outward and inward commensurate with demand. Measured service means cloud systems automatically control and optimize resource use by leveraging a metering capability appropriate to the type of service.

The service models include Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). IaaS provides basic computing infrastructure such as virtual machines and storage. PaaS provides a platform for developing, running, and managing applications. SaaS delivers software applications over the internet, on a subscription basis.

Deployment models include the public cloud, private cloud, community cloud, and hybrid cloud. A public cloud is owned and operated by a third-party provider. A private cloud is used exclusively by a single organization. A community cloud is shared by several organizations with common concerns. A hybrid cloud combines two or more clouds.