Images, containers, and Dockerfiles

An image is a stacked filesystem plus metadata; a container is a running instance of one. Every Dockerfile instruction is a layer.

What this lesson covers

• Distinguish an image from a running container
• Write a Dockerfile that builds reproducibly
• Choose a base image deliberately

This lesson sits in Containers and Images, part of DevOps with Docker and Kubernetes. It assumes what came before it and leads directly into the next lesson in the module.