Dockerfiles make images. They start with a base image and copy files into it to make the final image. But why do we need the base image? How do we know what's in it? What do we gain or lose by using that base image? Other than the file we put in, what else is in the final image?

Let's answer these questions with a mix of slides and demos. We'll go over the basics of what an image is made of. Spend time dissecting one. And even make our own from scratch. By the end of the session, we should have a better understanding of what an image is, and why it exists that way.