As you can see in the above diagram. A developer writes a code that stipulates application requirements or the dependencies in an easy to write
Docker File and this Docker File produces Docker Images. So, whatever dependencies are required for a particular application are present in this image.
Now, Docker Containers are nothing but the runtime instance of Docker Image. These images are uploaded onto the Docker Hub(Git repository for Docker Images) which contains public/private repositories.
So, from public repositories, you can pull your image as well and you can upload your own images onto the Docker Hub. Then, from Docker Hub, various teams such as Quality Assurance or Production teams will pull that image and prepare their own containers. These individual containers, communicate with each other through a network to perform the required actions, and this is nothing but Docker Networking.
So, you can define Docker Networking as a communication passage through which all the isolated containers communicate with each other in various situations to perform the required actions.
What do you think are the goals of Docker Networking?