Pi-hole Origins

Pi-hole being a advertising-aware DNS/Web server, makes use of the following technologies:

• dnsmasq - a lightweight DNS and DHCP server
• curl - A command-line tool for transferring data with URL syntax
• lighttpd - web server designed and optimized for high performance
• php - a popular general-purpose web scripting language
• AdminLTE Dashboard - premium admin control panel based on Bootstrap 3.x
• sqlite3 - SQL Database engine

While quite outdated at this point, this original blog post about Pi-hole goes into great detail about how Pi-hole was originally set up and how it works. Syntactically, it's no longer accurate, but the same basic principles and logic still apply to Pi-hole's current state.