Docker image registries

A Docker image registry hosts Docker images. Docker images are organized by tags that can be accessed and downloaded by users. These images can be used to create and run containers on a host machine. Image repositories can be hosted either locally or on a remote server, such as on Docker Hub, which is a public repository provided by Docker. You can also create your own private image repositories to share and distribute your images within your organization.

When you pull an image from a Docker image repository, the image is composed of multiple layers. Each layer represents an instruction in the Dockerfile that was used to build the image. These layers are stacked on top of each other to create the final image. Each layer is read-only and has a unique ID.

Thanks to UnionFS, the Docker registry shares common layers between multiple images and containers, reducing the amount of disk space required. When a container modifies a file, it creates a new layer...