Orientation brief

Images — The Blueprints

You've run containers. You've seen them start, do work, and stop. But where do containers come from? What's that thing you download before a container can run? That thing is an image. And understanding images is crucial because they're the foundation of everything in Docker. An image is not just "a file you download" — it's a carefully structured, layered, versioned blueprint that defines exactly what a container will be. In this module, we'll understand images deeply — what they are, how they differ from containers, where they come from, how versioning works, and how to explore them.

Understand the problem this module is here to solve.

Read 5 chapters in order, from context to application.

Practice the module concepts through focused exercises.

Chapter route

Read in order

Chapter 3.1 What is an Image? (The Blueprint Analogy)
Chapter 3.2 Images vs Containers — The Crucial Distinction
Chapter 3.3 Where Images Come From (Registries and Docker Hub)
Chapter 3.4 Image Tags and Versioning
Chapter 3.5 Exploring and Inspecting Images

Practice

Module exercises

Move from reading to investigation with scenario-based practice for this module.

Open exercises →