Docker Hub (https://hub.docker.com/) is the online registry provided by Docker. It can be used to publish public and private Docker images. This makes sharing and reusing Docker images extremely easy.
To get a Docker image from the registry, we just need to run docker pull <image-name>.
This makes it easy to use third-party tools without having to install them locally by just pulling and running the container from the registry. For example, if you want to run the Ubuntu OS via Docker, you can run the following command and it will provide you with a bash Terminal running on Ubuntu:
> docker run -e LANG=C.UTF-8 -e LC_ALL=C.UTF-8 -e TERM=$TERM -it --rm
ubuntu bash