Free ยท Lesson 1 of 12
Kubernetes runs containers. It does not replace the container runtime, and it does not install itself on a cloud until you ask a managed service to do that.
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A pod is one small boat. A node is the dock. The control plane is the harbour master who decides which dock gets the boat, and who sends a new boat if one sinks.
The control plane stores the desired state and makes decisions. The API server is the front door. etcd holds the cluster data. The scheduler picks a node. Controllers notice when the real world drifts from what you asked for.
A node runs the work. On the node, a kubelet talks to the API server, and a container runtime starts the containers. Your laptop can be one node. A cloud cluster is many nodes plus a control plane you often do not log into.
| Piece | What it decides | What it does not do |
|---|---|---|
| Control plane | Desired state, scheduling, and the API | It does not run your app containers |
| Node | Where pods are placed | It is not a backup of etcd |
| Container runtime | Starts and stops containers | It is not the Kubernetes API |
A container is a process with its own filesystem view. A Pod is the Kubernetes object around one or more containers that share a network namespace and can share volumes. You almost never create a bare Pod for a long-running app. A Deployment owns that.
A virtual machine includes a guest operating system. A container shares the node's kernel. Kubernetes schedules Pods, not virtual machines. Some clusters run Pods inside lightweight VMs for isolation. That is a node setup choice, not a different API.
The Kubernetes project publishes a new minor release about every four months. A minor version branch is maintained for about 14 months. Patch releases land on that branch.
This course does not name one patch as the version you must install. kubectl version and your cloud's version calendar are the numbers that matter. A tutorial that says "install 1.xx" without a date is already drifting.
Step 1 of 3kubectl sends the object to the API server. It does not start the container itself.
Step 2 of 3The API server checks the object and stores it. Controllers and the scheduler watch that store.
Step 3 of 3A kubelet on a node sees the Pod and asks the container runtime to start it.
You do not need a cluster yet. Say which sentence is about a Pod and which is about a node.
Pod: the smallest object Kubernetes runs. It can hold more than one container.
Node: a machine, virtual or physical, that runs Pods.
Control plane: the API and the decision makers. Not where your web server process lives.
Checked against the linked documentation in October 2026. A later release can move a flag, a price, or a supported pair. Use the page for the version you installed.