Kubernetes is a container orchestration platform built from a control plane (the kube-apiserver, etcd, kube-scheduler and kube-controller-manager) and a set of worker nodes running the kubelet and a container runtime. Every action you take flows through the API server, which writes desired state to etcd; controllers then reconcile actual state toward desired state.

As a CKAD you mostly interact with the cluster declaratively (YAML manifests applied with kubectl apply -f) or imperatively (kubectl run, kubectl create). Understanding the reconciliation loop explains why a deleted Pod managed by a Deployment is recreated automatically.

Key idea: you declare desired state; Kubernetes controllers continuously work to make actual state match it. You rarely manage individual Pods directly — you manage the controllers that own them.

🧠 Control plane brain⚙️ kubelet on nodes🔁 Reconcile loop📦 Desired state

🚢 Kubernetes Application Developer (CKAD)