PaaS (Platform as a Service)

A cloud computing model that provides a complete platform for developing, running, and managing applications without infrastructure complexity.

A cloud computing model that provides customers a complete platform -- hardware, software, and infrastructure -- for developing, running, and managing applications without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app.

PaaS sits between Infrastructure as a Service (IaaS) and Software as a Service (SaaS) in the cloud computing stack. While IaaS provides raw compute, storage, and networking, PaaS adds managed runtimes, databases, development tools, and deployment automation. Examples include Heroku, Google App Engine, and Azure App Service.

PaaS reduces the operational burden on development teams by handling operating system updates, patching, scaling, and load balancing. Developers deploy application code, and the platform manages everything below the application layer. Serverless platforms can be considered an evolution of PaaS, further abstracting away resource allocation and billing at the function or request level rather than the application level. API gateways on PaaS and serverless platforms provide managed routing and security without infrastructure management.