text: Figure 4-1 Red Hat OpenShift cluster platform components 
  
  **4.1.1 Docker service and Kubernetes**
  
  The Docker service that runs in every OpenShift cluster node provides the container image 
  administration. The Kubernetes cluster provides cluster management and orchestrates 
  containers on multiple nodes in the OpenShift cluster. 
  
  **4.1.2 etcd store**
  
  The etcd store is a distributed key value store that is used by Kubernetes to store 
  configuration and state information about the containers and resources that are inside the 
  OpenShift cluster. 
  
  **4.1.3 OpenShift-Kubernetes extensions**
  
  OpenShift-Kubernetes extensions are more resources that are used to save the OpenShift 
  configuration and cluster internal state. These resource extensions are stored in etcd with 
  application resources that are managed by Kubernetes. 