Glossary term
What is 0.0.0.0 (All network interfaces)?
0.0.0.0 stands for All network interfaces.
When a server binds here it accepts connections from any network the machine is on — reachable from outside if the firewall allows.
Learn it properly · DevOpsLesson 2: Networking Basics: IP, Ports, TCP/UDP and FirewallsHow a browser request actually finds and reaches your server. The layer Vercel hides completely, and the one you must understand before EC2 makes any sense.