A Platform-as-a-Service (PaaS) offering enables developers to develop, run and manage applications without having to worry about building and maintaining the infrastructure. This is done by the service provider, who also already provides certain services (storage, databases, development environments, etc.). These services can only be accessed via APIs (Application Programming Interface). PaaS offerings build on a scalable infrastructure (IaaS). PaaS environment ususally are the basis for Software as a Service (SaaS) offerings.
Most PaaS solutions are offered in one of three variants:
- Public Cloud - as described above
- Private cloud - unlike the public cloud, applications reside behind a firewall separate from third parties
- Hybrid Cloud - a mix of public and private clouds.
As with all cloud offerings, care must be taken as to where the data is ultimately stored and who has access to it and under what conditions (e.g., the U.S. Cloud Act allows access to all data stored by U.S. providers regardless of whose territory it is located on).