Docker images

The Docker image is like a template for a Docker container. It contains a set of folders and files that are necessary to start the Docker container. We will never have an image in execution mode. The image provides a template for Docker Engine to start up the container. We can create an analogy with object orientation to understand the process better. The image is like a class that provides an infrastructure to instantiate some objects, and instances are like a container.

Also, we have a Docker registry to store our images. These registries can be public or private. Some cloud vendors provide these private registries. The most famous is Docker Hub. It can be free, but if you choose this option, the image should be public. Of course, Docker Hub supports private images, but in this case, you have to pay for the service.