What is a Pod and why is it the smallest deployable unit?

A Pod is the smallest and simplest Kubernetes unit: one or more containers that share a network namespace and storage. It is the smallest deployable unit because the scheduler places Pods, not containers, and the IP address belongs to the Pod.

Its containers:

• share one IP address and port space, and reach each other on localhost
• can mount the same volumes
• are scheduled together onto the same node
• start and stop together as an atomic unit

That suits tightly coupled containers, such as an app and its log shipper.

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
  containers:
  - name: web-container
    image: nginx:1.20
    ports:
    - containerPort: 80