62 Red Hat OpenShift and IBM Cloud Paks on IBM Power Systems: Volume 1
Figure 4-2 shows a graphical view of OpenShift architecture components and how it works.
Figure 4-2   OpenShift Container Platform architectural components
The master nodes runs OpenShift core services, such as authentication, and provides the 
API entry point for administration. The nodes run applications inside containers, which are 
grouped into pods and then, the Kubernetes cluster divides the load between the cluster 
nodes.
OpenShift masters run the Kubernetes master services and etcd daemons, and at the same 
time, the nodes run the Kubernetes kubelet and kube-proxy daemons.
The masters are also nodes themselves. Scheduler, Management/Replication, and etcd are 
examples of Kubernetes master services. 
A pod is one or more containers that share a virtual network device, internal IP address, and 
storage. The Kubernetes skeduling process ensures that pods are assigned to nodes and 
that Kubelet service can run them. Skeduling is based on pod policies configuration. 
Scheduling decisions include individual and collective resource requirements, hardware and 
software/policy constraints, affinity and anti-affinity specifications, and others.
Kubernetes manages replicas to scale pods. A replica is a set of pods that share a definition. 
For example, a replica that consists of many Apache and PHP pods that are running the 
same container image can be used for horizontally scaling a web application.
4.1.8  OpenShift projects and applications
In 2.4, “Kubernetes: An open source container orchestration” on page 24, the Kubernetes 
resources where described. However, OpenShift also manages projects and users.