[Master Node - Control Plane]
Also known as master node or head node.
It manages the worker nodes in the cluster.
● API Server
It is the Gatekeeper of the cluster by providing Authentication, Authorization, Validation of all requests to perform CRUD (create, read, update, delete) functions in the cluster.
It responds to requests from the worker nodes.
● ETCD
It stores information about the state of the Cluster, the information Nodes and every other resources created with in the cluster.
It uses key-value pairs to store cluster data.
ETCD Storage is a key-value data store that can be accessed by all nodes in the cluster. It stores configuration data about the cluster’s state.
● Controller Manager
● Scheduler
It monitors resource utilization across the cluster and schedules pods of containers accordingly.

[Worker Node]
Also known as worker node or compute node.
Kubernetes cluster needs at least one worker node, but normally have many.
It can scale up and scale down cluster by adding and removing nodes.
● Kubelet
It maintain to register the node with the cluster.
It will send periodic health check so that the API server know that compute nodes (worker nodes) are healthy.
It will also create and destroy workloads as directed by Kube API server.
● Kube Proxy
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