What is a Pod in Kubernetes and why is it not just a container?
A Pod is the smallest deployable unit in Kubernetes: one or more containers that share an IP address, ports and volumes and are always scheduled together on the same node. Most Pods hold one main container.
Explain it simply
A Pod is a flat, and containers are the flatmates. They share one address, one electricity meter (volumes) and can talk over 'localhost', but the flat is bought, moved and sold as a whole.
Kubernetes never runs a bare container; it wraps it in a Pod. All containers in a Pod share the network namespace, so they reach each other at localhost:port, and they can mount the same volumes. They always land on the same node and live and die together. Typical Pods have one app container. Extra containers are helpers, called sidecars, such as a log shipper or a proxy.
Pods are mortal: if one dies, it is not repaired but replaced by a new one with a new IP. That is why you rarely create Pods directly. You use a Deployment, which keeps the desired number alive.
Example
apiVersion: v1
kind: Pod
metadata:
name: web
spec:
containers:
- name: nginx
image: nginx:1.27
ports:
- containerPort: 80What to say in the interview
"A Pod is the smallest deployable unit: one or more containers sharing network, storage and node. They are ephemeral, with changing IPs, so I manage them through controllers like Deployments rather than creating them by hand."
Common mistakes
- Creating bare Pods in production, where nothing recreates them if the node fails.