PaaS

A cloud model providing a managed platform for building applications.

Platform as a Service provides a managed environment, including operating system, runtime, and middleware, on which customers build and deploy applications without managing the underlying infrastructure. Under the shared responsibility approach, the provider secures the platform and below, while the customer remains responsible for application code, configuration, and data. This shifts patching of the platform to the provider but does not remove the need for secure development and access control. PaaS sits between IaaS, which exposes more infrastructure, and SaaS, which delivers finished software.