RedHat OpenShift platform is an example of a PaaS type of service. According to OpenShift 4.4 manual
OpenShift Container Platform is a platform for developing and running containerized applications. It is designed to allow applications and the data centers that support them to expand from just a few machines and applications to thousands of machines that serve millions of clients. With its foundation in Kubernetes, OpenShift Container Platform incorporates the same technology that serves as the engine for massive telecommunications, streaming video, gaming, banking, and other applications. Its implementation in open Red Hat technologies lets you extend your containerized applications beyond a single cloud to on-premise and multi-cloud environments.
It is based on Kubernetes, which is an open source production-grade container orchestration. The containers (e.g. Docker container technology) are the widely used building blocks for modern application development and they can be run in a different platforms, for example on the personal computers of the application developers and testers, as well as on a scalable cloud infrastructure. Kubernetes is the de-facto orchestrating platform for containers, as they enable a reliable and flexible distribution system for containerized cloud services and applications.
The architecture of the OpenShift Platform is seen below.
Picture 5. OpenShift platform architecture.