Glossary term
What is localhost (localhost / 127.0.0.1)?
localhost stands for localhost / 127.0.0.1.
“This same machine only.” A service bound here cannot be reached from outside the server.
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.