Port Number
A numeric label that directs network traffic to the right program on a device. Combined with an IP address, it tells data exactly where to go.
Full Definition
A port number is a 16-bit integer (0–65535) that identifies a specific process or service on a host. IP addresses identify machines; port numbers identify the service on that machine. Well-known ports include 80 (HTTP), 443 (HTTPS), 22 (SSH), 3128 (common proxy default), and 1080 (SOCKS). Proxy servers are typically accessed via a specific IP:port combination. Backconnect proxy providers assign you a gateway host and port; requests go to that port and the provider routes them through its pool. Corporate firewalls often block non-standard ports, which is why many services run on 443 to appear as HTTPS traffic.
