● SaaS (Software as a Service)
● PaaS (Platform as a Service)
● IaaS (Infrastructure as a Service)
Software as a Service (SaaS) is a software delivery model in which software and its associated data are hosted
centrally in the cloud and typically accessed using a web browser over the Internet. SaaS has become a
common delivery model for many business applications, including accounting, collaboration, customer relationship management (CRM), enterprise resource planning (ERP), invoicing, human resource management (HRM), content management (CM) and service desk management.
Platform as a Service (PaaS) is the delivery of a computing platform and solution stack as a service. PaaS
offerings facilitate deployment of applications without the cost and complexity of buying and managing the underlying hardware and software and provisioning hosting capabilities, providing all of the facilities required to support the complete life cycle of building and delivering web applications and services entirely available from the Internet. PaaS offerings may include facilities for application design, application development, testing, deployment and hosting as well as application 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. These services may be provisioned as an integrated solution over the web.
Infrastructure as a Service (IaaS) 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.