Kubernetes - Core Concepts & Architecture

The master management layer of a Kubernetes cluster that maintains the desired cluster state, makes global scheduling decisions, and responds to events via components like kube-apiserver, etcd, kube-scheduler, and kube-controller-manager.

The central management front-end of the Control Plane that exposes the Kubernetes API. It validates and processes RESTful requests from users, external services, and worker node components.

A consistent, highly available distributed key-value store used as Kubernetes' primary backend database to store all cluster state data and object specifications.

The Control Plane component that monitors for unassigned Pods and selects an optimal worker node for them to run on based on resource availability, constraints, affinity policies, and taints/tolerations.

A single control plane binary running continuous background control loops (e.g., Node Controller, ReplicaSet Controller) that compare current state against desired state and make reconciliation adjustments.

The primary node agent running on every worker node. It reads PodSpec manifests, communicates with the container runtime to start/stop containers, and reports node health back to kube-apiserver.

A network proxy running on each node that maintains local network rules, handling IP/port forwarding and enabling network communications to Pods across internal and external network requests.

The underlying software responsible for running containers on a node (e.g., containerd, CRI-O). It pulls container images, executes them, and manages their container execution lifecycle.