These are the core building blocks you'll use in nearly every Docker command. Once they're clear, the rest of the course is mostly variations on them.
An image is a read-only template containing an application and everything it needs to run. A container is a running (or stopped) instance created from an image, and one image can produce many containers. You work with both through the Docker CLI: pulling images, starting and stopping containers, listing what's running, and cleaning up.
Two more pieces complete the picture. Volumes keep data outside a container's writable layer, so it survives when the container is removed. Networks let containers talk to each other and the outside world while staying isolated from unrelated containers by default. Watch the lessons in order, then continue on to Data Persistence & 3rd Party Images.
The difference between Docker images and containers, shown with an nginx web server and a cookie analogy. Everything else in Docker builds on this distinction.
A beginner-friendly crash course on getting started with Docker, and a good place to practice the everyday CLI commands from this module.
What a container's writable layer is, why your data disappears when a container is removed, and how the different kinds of mounts keep it.
A practical look at Docker's default bridge network and how to create custom networks so containers can communicate.
A fast recap of the core Docker concepts, a good way to check that the pieces from this module fit together.