What is the Difference Between Docker and Kubernetes

Containers changed how we deploy software. But Docker and Kubernetes do different things — here’s what you need to know.

What is Docker?

Docker creates containers. It packages your app with all dependencies so it runs the same everywhere.

• Builds container images from your code
• Runs containers on a single machine
• Solves the “works on my machine” problem

What is Kubernetes?

Kubernetes manages containers at scale. It doesn’t build containers — it orchestrates them across multiple servers.

• Distributes containers across a cluster
• Auto-restarts crashed containers
• Scales up/down based on demand
• Handles load balancing

Docker vs Kubernetes: Comparison

Aspect	Docker	Kubernetes
Purpose	Build and run containers	Orchestrate containers at scale
Scope	Single machine	Multiple machines (cluster)
Scaling	Manual	Automatic
Self-Healing	No	Yes — restarts failed containers
Load Balancing	Basic	Built-in
Setup	Simple	Complex
Best For	Development, small deployments	Production, microservices

When to Use Each

Use Docker alone:

• Local development
• Small apps on one server
• CI/CD pipelines

Add Kubernetes:

• Production workloads needing high availability
• Multiple services across servers
• Auto-scaling requirements

How They Work Together

Docker builds the image → Push to registry → Kubernetes deploys and manages it

They’re not competitors — Docker packages, Kubernetes orchestrates.

---

Summary

Docker = container builder
Kubernetes = container manager

Start with Docker. Add Kubernetes when you need scale and reliability.