Ansible Galaxy is a number of things: first and foremost, it is a website that can be found at https://galaxy.ansible.com/. The website is home to community contributed roles and modules:

So far, we have been writing our own roles that interact with the Ansible Core modules for use in our playbook. Rather than writing our own roles. we could be using one of the more than 15,000 roles published on Ansible Galaxy—these roles cover a multitude of tasks and support pretty much of all of the operating systems supported by Ansible.

The ansible-galaxy command is a way of interacting with the Ansible Galaxy website from the comfort of your own command line, as well as being able to bootstrap roles. Just as we have been using it in previous chapters, we can also use it to download, search and publish our own roles on Ansible Galaxy.

Finally, Red Hat has open sourced the code for Ansible Galaxy, meaning that you can also run your own version of the site should you need to distribute your own roles behind a firewall.