Software as a service (SaaS)
These applications are accessible from various client devices through either a thin client interface (such as a web browser) or a program interface. Where the end user does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
Platform as a service (PaaS)
The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider.
Infrastructure as a service (IaaS)
The capability to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications but does not manage or control the underlying cloud infrastructure.