About Docker Basics

What containers are, why they're useful, first run, common pitfalls. Part of the DevTools Surf developer suite. Browse more tools in the Info / Guides collection.

Use Cases

• Junior developers understanding containers for the first time
• Students setting up consistent development environments across machines
• Backend devs learning to containerize a Node.js or Python application
• Bootcamp instructors teaching infrastructure fundamentals

Tips

• Read the 'first run' section before installing Docker Desktop
• Check the common pitfalls list to avoid volume mount mistakes
• Review the container vs VM comparison to understand the difference

Fun Facts

• Docker was released by Solomon Hykes at PyCon 2013 as an internal tool from dotCloud. The company later renamed itself to Docker, Inc.
• Docker containers share the host kernel, making them up to 50x faster to start than virtual machines — typically under 1 second.
• The Docker Hub registry surpassed 13 billion image pulls per month by 2023, making it the largest container image registry in the world.

FAQ

What is a container?

A packaged application + its dependencies in an isolated process. Similar to a VM but shares the host kernel, so it's much lighter.

Image vs container?

Image is the blueprint (read-only). Container is a running instance (read-write). You can have many containers from the same image.

First commands to know?

docker pull (download image), docker run (start container), docker ps (list running), docker logs (see output), docker exec (shell into a container).

What goes wrong first?

Port conflicts (two containers on the same host port), volume mounts with wrong paths, and forgetting that data in a container is ephemeral without a volume.