Docker

Learn Docker step by step — simple English, real diagrams, real Node.js and React examples. Start from "why does Docker exist" and build up to production-ready images.

Lessons

1. Why Docker Exists — The works-on-my-machine problem, VMs vs containers, the shared kernel, and how images travel through Docker Hub.
2. Dockerfile Instructions Explained — All 13 instructions from FROM to VOLUME, what Docker does internally at each line, and the classic interview pairs.

New to Docker? Start with Why Docker Exists — everything else builds on it.