Docker reduces the logical view of your infrastructure to three core components: hosts, containers, and images. Hosts run containers, which are isolated instances of an application. Containers are created from images, which are packaged applications. The Docker container image is conceptually very simple - it's a single unit that contains a complete, self-contained application. The image format is very efficient, and the integration between the image and the runtime is very smart, so mastering images is your first step to using Docker effectively.
You've already seen some images in Chapter 1, Getting Started with Docker on Windows, by running some basic containers to check your Docker installation was working correctly - but I didn't look very closely at the image or how Docker used it. In this chapter, you...
