Kubernetes is a container orchestration system that solves critical limitations of running Docker alone, such as single-host resource contention, lack of auto-healing, and no auto-scaling. It manages container lifecycles across multiple machines to ensure application reliability. The architecture consists of two main planes: the Control Plane and the Data Plane.

The Control Plane manages the cluster state via components like the API Server (the front door for all commands), etcd (a key-value store for cluster data), the Scheduler (assigns Pods to nodes), and the Controller Manager (ensures the desired state is met). The Data Plane executes the workloads. It includes the Kubelet (an agent that runs Pods on nodes), Kube-proxy (handles networking and load balancing), and the Container Runtime (like containerd or CRI-O).

Understanding this flow—from API request to etcd storage, scheduling, and Kubelet execution—is essential for mastering container orchestration and building scalable, self-healing infrastructure.