Port mapping is the process of identifying which network ports are exposed on a device and what services listen on them. A port is a numbered entry point for network communication, so mapping ports helps determine whether a device is running web administration, remote access, file sharing, proxy services, or other applications.
In cyber security, port mapping matters because exposed ports often reveal attack surface. Attackers use it to find weak services, guess device types, and decide where malware can connect, pivot, or relay traffic. Defensive teams use the same idea to inventory exposed services, reduce unnecessary open ports, and spot unusual changes. On routers and other edge devices, port mapping can show whether management interfaces are reachable from the internet or whether a device has been repurposed as hidden infrastructure. Careful port review, combined with patching and access controls, helps limit abuse.