Let's explore some keywords that we encountered earlier in this recipe:
- Images: Docker images are read-only templates, and they give us containers during runtime. They are based on the idea of a base image and layers resting on top of it. For example, we can have a base image of Alpine or Ubuntu, and then we can install packages or make modifications over the base image to create a new layer. The base image and new layer can be treated as a new image. For example, in the following figure, Debian is the base image and then Emacs and Apache are the two layers added on top of it. They are highly portable and can be shared easily:
Layers are transparently laid on top of the base image to create a single coherent filesystem. ...