Docker's pitch is simple: package an application with all of its dependencies into a single, isolated unit, and it runs the same way everywhere. No more "it works on my machine."

If you have never run a container before, this guide gets you from zero to a running container in about ten minutes — and explains what is actually happening at each step.

Images vs. containers

Two terms you need straight away:

An image is a read-only blueprint. Think of it like a class definition.

A container is a running instance of that image. Think of it like an object instantiated from the class.

You pull an image once, then run as many containers from it as you like.

Prerequisites

Install Docker Engine for your platform (Docker Desktop on macOS and Windows, Docker Engine on Linux), then verify it works:

docker --version

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If a version number prints, you are ready.

Step 1: Pull a base image

Images live in registries, usually Docker Hub.…