Intro To Plone Stack#
If you haven't read the first couple of chapters of Guide to deploying and installing Plone in production, take a moment to do so.
You'll want to be familiar with the main components of a typical Plone install for deployment and know when each is vital and when unnecessary.

The generic components of a full-stack Plone installation. Not all are always used.#
The Plone Ansible Playbook makes choices for each generic component.

The specific components used in Plone's Ansible Playbook.#
You are not stuck with our choices!
If, for example, you wish to use Apache rather than Nginx for the web server component, that won't be a particular problem. You'll need to do more work to customize.