Plain-English definitions of the Kubernetes terms for CKA study. Simplified for learning; the official Kubernetes documentation is authoritative.
| Term | Definition |
|---|---|
| Pod | The smallest deployable unit; one or more containers sharing a network and storage. |
| Node | A worker machine that runs pods. |
| Control plane | The components that manage the cluster (API server, scheduler, controller manager, etcd). |
| etcd | The key-value store holding all cluster state; backed up and restored in the exam. |
| Deployment | Manages a replicated set of pods and rolling updates. |
| ReplicaSet | Keeps a stable number of pod replicas running. |
| Service | A stable network endpoint for a set of pods. |
| Ingress | Routes external HTTP/S traffic to services. |
| ConfigMap | Non-secret configuration injected into pods. |
| Secret | Sensitive data (passwords, tokens) injected into pods. |
| PersistentVolume (PV) | Cluster storage provisioned for use by pods. |
| PersistentVolumeClaim (PVC) | A pod’s request for storage. |
| StorageClass | Defines how storage is dynamically provisioned. |
| NetworkPolicy | Rules controlling traffic between pods. |
| RBAC | Role-Based Access Control: Roles and RoleBindings granting permissions. |
| kubeadm | Tool to bootstrap and manage a cluster. |
| kubectl | The command-line tool to operate the cluster. |
| Namespace | A virtual cluster used to scope resources. |
| Taint / Toleration | Mechanisms controlling which pods schedule onto which nodes. |
| CoreDNS | The cluster’s DNS for service discovery. |