Docker Repository vs Docker Registry

Docker registry is a service that is storing your docker images.

Docker registry could be hosted by a third party, as public or private registry, like one of the following registries:

• Docker Hub,

• Quay,

• Google Container Registry,

• AWS Container Registry

or you can host the docker registry by yourself (see https://docs.docker.com/ee/dtr/ for more details).

Docker repository is a collection of different docker images with same name, that have different tags.

Tag is alphanumeric identifier of the image within a repository.

For example see https://hub.docker.com/r/library/python/tags/. There are many different tags for the official python image, these tags are all members of the official python repository on the Docker Hub. Docker Hub is a Docker Registry hosted by Docker.