Clarifying the Docker terms

To make this chapter substantially simpler to understand and to minimize any kind of ambiguity, the frequently used terms will be explained in the following section.

Docker images and containers

A Docker image is a collection of all of the files that make up a software application. Each change that is made to the original image is stored in a separate layer. To be precise, any Docker image has to originate from a base image according to the various requirements. Additional modules can be attached to the base image for deriving the various images that can exhibit the preferred behavior. Each time you commit to a Docker image you are creating a new layer on the Docker image, but the original image and each pre-existing layer remains unchanged. In other words, images are typically of the read-only type. If they are empowered through the systematic attachment of newer modules, then a fresh image will be created with a new name. The Docker images are turning out to...