Shipping applications is an integral part of the Docker platform. The Docker service can download images from a central location to run containers from them, and also upload images that were built locally to a central location. These shared image stores are called registries, and in this chapter I'll look more closely at how image registries work and the type of registries that are available to you.
The primary image registry is Docker Hub, which is a free online service and is the default location for the Docker service to work with images. Docker Hub is a great place for the community to share images built to package open source software that is free to redistribute. Docker Hub has been hugely successful. At the time of writing this book, there are over 600,000 images available on the Hub, with over 12 billion downloads...
