Understanding Docker images

Docker images form the blueprint of Docker containers. Just like you need a blueprint for a shipping container to determine its size and what goods it will contain, a Docker image specifies what packages, source code, dependencies, and libraries it needs to use. It also determines what it needs to do for the source code to run effectively.

Technically, it consists of a series of steps you would perform on a base OS image to get your application up and running. This may include installing packages and dependencies, copying the source code to the correct folder, building your code to generate a binary, and so on.

You can store Docker images in a container registry, a centralized location from where your Docker machines can pull images to create containers.

Docker images use a layered filesystem. Instead of a huge monolithic block on the filesystem that comprises the template to run containers, we have many layers, one on top of the other. But what...