An internet-facing host is any server, workstation, appliance, or cloud instance that can be reached directly from the public internet. That exposure may be intentional, such as a web server or VPN gateway, or accidental, such as a database, repository service, or admin console left open without network restrictions.
This term matters because public reachability makes a system discoverable by scanners and attackers. Once a host is exposed, it can be probed for weak authentication, unpatched software, open ports, leaked secrets, or misconfigurations. In the context of exposed Git repositories, internet-facing hosts are the systems an attacker can enumerate to find public code stores and search for credentials or sensitive files. Defenses include minimizing exposure, using firewalls and security groups, requiring strong authentication, patching services, and monitoring externally visible assets.