Port
Domain: Computer Systems
🎯 Motivation
A numbered endpoint for network communication. Each service uses a specific port.
📋 Concrete Example
Ports: 80 (HTTP), 443 (HTTPS), 22 (SSH), 5432 (PostgreSQL). A server listens on these ports. Clients connect to the right port for the right service.
🔗 Analogy
A port is like an apartment number in a building - the building (server) has many apartments (ports). You go to apartment 443 (HTTPS) for web, apartment 22 (SSH) for remote access.