Platform as a Service (PaaS)

Platform as a Service (PaaS) is a cloud computing model that provides users with a cloud-based environment to develop, run, and manage applications without having to build and maintain the underlying infrastructure. PaaS sits in the middle between Infrastructure as a Service (IaaS) and Software as a Service (SaaS) as part of the cloud computing stack.

With PaaS, the cloud provider hosts the hardware and software on their infrastructure. This includes the servers, storage, networking, operating system, middleware, databases and other services. Users access these resources via the internet to develop and deploy applications using programming languages, libraries, services and tools supported by the PaaS provider. For example, a PaaS provider like Heroku allows developers to use languages like Ruby, Java, Python, Node.js, etc. to build web apps. The apps are hosted on Heroku's servers and the developers don't have to provision their own VMs or manage the underlying infrastructure. This enables faster development and deployment of apps without IT overhead. Other examples of PaaS include AWS Elastic Beanstalk, Microsoft Azure App Service, Google App Engine and Red Hat OpenShift.