The web server configuration parameter host is the IP address on which the server listens. The most common settings are:
- 127.0.0.1 (default) - only listens for connections from browsers on the same computer
- 0.0.0.0 - listens for connections on all network interfaces, and thus from any browser on a reachable network
- n.n.n.n - listens for connections on the network interface with the specified IP address
Note: Using 0.0.0.0 or n.n.n.n in a public environment (e.g. coffee shop, library, airport) is inadvisable as it will expose your system to possible intrusion.