Important Kubernetes Concepts

Core Concept	Topics	Concepts	Short Description	Important Pointers
Core Architecture	Control Plane	API Server	Entry point for all cluster operations	All components communicate via API Server; Q: What happens when you run kubectl apply?
		Scheduler	Assigns Pods to Nodes	Uses resources & constraints; Q: How scheduling decision is made?
		Controller Manager	Runs controllers	Maintains desired state (reconciliation loop)
		etcd	Distributed key-value store	Strong consistency; critical component
	Worker Node	Kubelet	Manages pods on node	Talks to API Server
		Kube Proxy	Manages networking rules	Q: Why kube-proxy is needed?
		Container Runtime	Runs containers	containerd / CRI-O
Workloads	Pod	Pod	Smallest deployable unit	Ephemeral; Q: Why Pods are not created directly?
	Controllers	Deployment	Manages stateless apps	Q: Difference: Deployment vs StatefulSet
Networking	Services	ClusterIP	Internal communication	Q: How Pod A talks to Pod B?
	Routing	Ingress	HTTP/HTTPS routing	Q: Difference: Service vs Ingress
Storage	Persistent Storage	PersistentVolume	Actual storage resource	Q: PV vs PVC
Configuration	Config	ConfigMap	Non-sensitive config	Q: ConfigMap vs Secret
Scheduling	Placement	NodeSelector	Basic scheduling	Q: Difference: affinity vs nodeSelector
Scaling	Autoscaling	HPA	Scales pods	Q: How HPA works internally?
Observability	Logging	Logs	Container logs	Q: How to debug a failing pod?
Deployment	Strategies	Rolling Update	Gradual rollout	Q: How to achieve zero downtime deployment?
Ecosystem	Tools	Helm	Package manager	Q: Helm vs Kustomize
	GitOps	Argo CD	GitOps deployment	Q: What is GitOps?
Extensibility	Pattern	Operator	Automates apps	Q: What is Operator pattern?
Advanced	Service Mesh	Istio	Traffic management	Q: Why service mesh?