Kubernetes Control Plane and Data Plane Concepts
Internal
Cluster
A Kubernetes cluster consists of a set of nodes. Of those, a small number are master nodes, which are collectively known as the control plane, and a potentially relatively larger number of worker nodes, which run the cluster's workload.
Node
A node can be a master or worker.
Control Plane
The control plane is the cluster's set of master nodes. The control plane exposes the API via the API Server and contains the cluster store, controller manager, scheduler and other management components. The control plane makes workload scheduling decisions, performs monitoring and responds to external and internal events.
Master Node
The master nodes are sometimes called heads or head nodes. Collectively, they represent the control plane.
Control Plane Components
API Server
Cluster Store
Controller Manager
Scheduler
Cloud Controller Manager
Data Plane
Worker Node
A worker node is where the application services run.