Localhost-11501 [portable] Direct

A port is a virtual endpoint for network communication. Think of your computer as an apartment building; the IP address (127.0.0.1) is the street address, and the (like 11501) is the specific apartment number.

const express = require('express'); const app = express(); const PORT = 11501; localhost-11501

curl http://localhost:11501

Traffic sent to the loopback interface does not leave the computer. It is routed back to the operating system’s networking stack, ensuring security and speed. A port is a virtual endpoint for network communication

If another application is already using port 11501, your new service will fail to start. const app = express()