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. Hardware port: CPU transmits data with peripherals through interface registers or specific circuits, which is called a port. The ports in the hardware field are also called interfaces, such as parallel ports and serial ports.
Network port: In network technology, a port has several meanings. The ports of hubs, switches and routers refer to the interfaces connecting other network devices, such as RJ-45 port and serial port. The port mentioned here is not a physical port, but a port in TCP/IP protocol and a logical port.
Extended data:
On the Internet, each host sends and receives data packets through TCP/ip protocol, and each data packet is routed in the Internet according to the ip address of its destination host, and the data packet is successfully transmitted to the destination host. Most operating systems support multiple programs (processes) running at the same time, so which process should the destination host send the received packets to? Obviously, this problem needs to be solved, so the port mechanism is introduced.
The local operating system will assign protocol ports to those processes that need them, and each protocol port will be identified by a positive integer, such as: 80,139,445 and so on. After receiving the data packet, the destination host will send the data to the corresponding port according to the destination port number of the message header, and the process corresponding to this port will receive the data and wait for the arrival of the next group of data. Speaking of which, the concept of port still seems abstract. Keep following me and don't go away.