"port" is a free translation of English port, which can be considered as the exit of communication between equipment and the outside world. Ports can be divided into virtual ports and physical ports, where virtual ports refer to the ports inside the computer or in the switch router and are invisible.
A domain name is the name of a computer or computer group on the Internet, which consists of a series of names separated by dots. Used to identify the electronic location of the computer in the process of data transmission (sometimes refers to the geographical location, geographical domain name, refers to the local area with administrative autonomy). A domain name is an IP address with a "mask".