Port

A port is a channel of a device that supports a single point-to-point connection. For single-port devices such as
modems, the device and the port are indistinguishable. For multiport devices, the port is the subdivision of the
device over which a separate point-to-point communication is possible. For example, Primary Rate Interface (PRI)
ISDN adapters support two separate channels called B channels. The ISDN adapter is a device. Each B channel is a
port because a separate point-to-point connection occurs over each B channel.