Port Binding

Definitions

The practice of a service binding to a network port to listen for incoming requests, making itself available as a self-contained, externally accessible process. One of the twelve-factor app principles, it means the app exports HTTP (or other protocols) by binding to a port rather than relying on an external web server container.
In plain English: When a program claims a specific port number on the computer to receive network traffic, like reserving a specific phone extension.
Example: "Each microservice does its own port binding — the user service listens on 3001, auth on 3002, and the gateway on 80."