K3s and Kubernetes Explained: Nodes, Manifests, and Key Commands in One Guide

K3s is a lightweight Kubernetes distribution where clusters are built from nodes — machines that serve as either server/master nodes for cluster management or agent/worker nodes for running workloads. Core components such as kube-apiserver, etcd, kube-scheduler, and kubelet handle communication, state storage, scheduling, and pod execution respectively. Administrators interact with the cluster by submitting YAML manifests via kubectl, which communicates with the API server to record and apply the desired state. Kubernetes also supports labels as key-value metadata for filtering and organizing pods within namespaces, though they cannot replace namespaces themselves. ConfigMaps provide a way to store non-sensitive configuration data in key-value pairs, which can be injected into containers as environment variables, CLI arguments, or mounted files.