Docker Compose lets you run multiple Docker containers together with a single command. Instead of starting each container manually, you define everything in a docker-compose.yml file and run docker compose up.

The problem it solves

Most apps need more than one container. A typical web app needs:

• Your app (Node.js, Python, etc.)
• A database (PostgreSQL, MySQL)
• Maybe Redis for caching
• Maybe Nginx as a reverse proxy

Without Compose, you’d run each container separately:

docker run -d --name db -e POSTGRES_PASSWORD=secret postgres
docker run -d --name redis redis
docker run -d --name app --link db --link redis -p 3000:3000 my-app

With Compose, one file, one command:

# docker-compose.yml
services:
  app:
    build: .
    ports:
      - "3000:3000"
    depends_on:
      - db
      - redis

  db:
    image: postgres
    environment:
      POSTGRES_PASSWORD: secret
    volumes:
      - db-data:/var/lib/postgresql/data

  redis:
    image: redis

volumes:
  db-data:

docker compose up      # Start everything
docker compose down    # Stop everything

Key features

• Networking — containers can talk to each other by service name (db, redis). No manual linking.
• Volumes — persistent data survives container restarts.
• Environment variables — configure each service.
• Dependencies — depends_on controls startup order.
• One command — docker compose up -d starts your entire stack.

When to use Docker Compose

Good fit: local development environments, small self-hosted apps, running multiple services together, CI/CD test environments.

Not ideal: production at scale (use Kubernetes), single-container apps (just use docker run).

For the full command reference, see the Docker Compose cheat sheet. See also: What is Docker? | Docker cheat sheet