Platform as a Service (PaaS) or application platform as a Service (aPaaS) or platform base service is a category of cloud computing services that provides a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app. PaaS can be delivered in three ways:
• as a public cloud service from a provider, where the consumer controls software deployment with minimal configuration options, and the provider provides the networks, servers, storage, operating system (OS), middleware (e.g. Java runtime, .NET runtime, integration, etc.), database and other services to host the consumer's application.
• as a private service (software or appliance) inside the firewall.
• as software deployed on a public infrastructure as a service.
Public PaaS is derived from software as a service (SaaS), and is situated in cloud computing between SaaS and infrastructure as a service (IaaS).SaaS is software that is hosted in the cloud, so that it doesn't take up hard drive from the computer of the user or the servers of a company. IaaS provides virtual hardware from a provider with adjustable scalability.With IaaS, the user still has to manage the server, whereas with PaaS the server management is done by the provider.
Amazon AWS, Oracle Cloud Platform, Jelastic and Heroku are some of the commercial public cloud PaaS providers.
A private PaaS can typically be downloaded and installed either in a company's on-premises data center, or in a public cloud. Once the software is installed on one or more machines, the private PaaS arranges the application and database components into a single hosting platform. Private PaaS vendors include Apprenda, which started out on the Microsoft .NET platform before rolling out a Java PaaS; Red Hat's OpenShift and Pivotal Cloud Foundry.
Hybrid PaaS is typically a deployment consisting of a mix of public and private deployment