TL;DR
Docker is a container runtime: it packages an application into an image and runs it on one machine. Kubernetes (K8s) is a container orchestration platform: it schedules, scales, heals, and load-balances containers across a cluster of machines. For local dev and small projects, Docker Compose is enough; adopt K8s when you need multi-node high availability, autoscaling, or self-healing.
Comparison
| Aspect | Docker | Kubernetes |
|---|---|---|
| Role | Container runtime | Container orchestration |
| Scope | Single machine | A cluster (many machines) |
| Packaging | Dockerfile → image | Reuses images; defines Pods/Deployments |
| Autoscaling | No | Yes (HPA by CPU/custom metrics) |
| Self-healing | No | Restarts/reschedules failed Pods |
| Service discovery | Manual port mapping | Service + Ingress + DNS |
| Rolling updates | Manual | Built-in rollout and rollback |
| Learning curve | Low | High (networking, storage, RBAC) |
| Best for | Dev, single host, small projects | Production clusters, microservices |
Which one when
- Local dev, personal projects, one VPS: Docker + Compose.
- Multiple interdependent services started with one command: Compose.
- Multi-node, HA, autoscaling, zero-downtime releases: K8s.
- To avoid operating K8s yourself: managed services (EKS/GKE/ACK) or lightweight distros like k3s.
FAQ
Are Docker and Kubernetes alternatives?
No. Docker runs containers; Kubernetes orchestrates them. K8s nodes still use a container runtime (typically containerd) to run containers.
What's the difference between Docker Compose and Kubernetes?
Compose runs multiple containers on one host from a compose file; it has no autoscaling, self-healing, or cross-node scheduling. K8s provides those capabilities across a cluster.
How many machines do I need to learn Kubernetes?
For learning, minikube or k3s on a single machine works. A production HA cluster typically uses 3 control-plane nodes (odd count for etcd quorum) plus at least 2 workers.
Sources
- Docker docs (docs.docker.com), accessed 2026-08-04
- Kubernetes docs (kubernetes.io/docs), accessed 2026-08-04