pages.charlesreid1.com is a static site-hosting deployment solution provided by git.charlesreid1.com.
What is a static site?
A static site is just a pile of static HTML, Javascript, CSS, and other files that can be sent over to the host, and the host can render everything on their end. (Compare with a dynamic site, which uses a language like PHP that requires the server to do the computations.)
What does pages.charlesreid1.com provide?
This provides a subdomain for hosting static sites associated with the repositories in git.charlesreid1.com.
It is a private, self-hosted solution that offers much of the same thing as what Github Pages (or simple Heroku projects) offer.
How is it hosted?
This uses nginx, a fast, reliable, and easily-configurable web server. The server with the static content is reverse-proxied by the frontend server, which establishes secure connections and owns all of the SSL certificates.
Who is this for?
Pages can only be created/modified by users of git.charlesreid1.com (i.e., me). They can be viewed by anyone (i.e., you).