Platform as a service
Platform as a service (PaaS) or application platform as a service (aPaaS) or platform-based 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.
Development and uses
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) behind a firewall.
As software deployed on a public infrastructure as a service
Public, private and hybrid
There are several types of PaaS, including public, private and hybrid. PaaS was originally intended for applications on public cloud services, before expanding to include private and hybrid options.
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 hosted in the cloud, so that it does not take up hard drive space on the computers of users. 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.
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.
Hybrid PaaS is typically a deployment consisting of a mix of public and private deployments.