The article discusses setting up Split-Horizon DNS with AdGuard Home to enable accessing a self-hosted app from both home and VPN networks. Split-Horizon DNS allows the DNS server to return different IP addresses based on the network the request is coming from, simplifying the setup process. By configuring custom filtering rules in AdGuard Home, one DNS server can provide different IP addresses for the app domain depending on the network location, eliminating the need for running multiple DNS servers. This solution offers a streamlined approach for managing DNS responses for different network environments while ensuring connectivity for devices with or without VPN access.