Docker lets you package an app with everything it needs (system libs, runtime, config) so it runs the same everywhere.

  • A Docker image is a recipe (read-only).
  • A container is a running instance of that image.
  • You define images with a Dockerfile → build → run. 
# Build an image from Dockerfile docker build -t hello . # Run it (maps port 3000) docker run -p 3000:3000 hello

That’s it—portable apps, fewer “it works on my machine” moments.

Originally published on Bitlyst.