2.USB ports are data ports, control ports and status ports. USB is an external bus standard, which is used to standardize the connection and communication between computers and external devices.

3.COM1,COM2 and COM3 are all COM ports, which are referred to as serial communication ports for short.

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.

COM port: Motherboards usually have two COM serial ports. It is usually used to connect a mouse and communication equipment (such as connecting an external modem for data communication). The COM port connector on PC is usually a 9-pin male D-shell interface. The definition of COM pin is the same as that of RS-232C interface (DB9).

Extended data:

Port type:

1, well-known port

Well-known ports are well-known port numbers ranging from 0 to 1023, of which 80 ports are allocated to WWW service and 2 1 ports are allocated to FTP service. We don't need to specify the port number when we enter the URL in the address bar of IE, because by default, the port of WWW service is "80".

2. Dynamic port

The range of dynamic ports is from 49 152 to 65535. It is called a dynamic port because it generally does not allocate a service fixedly, but dynamically.

3. Register the port

Ports 1024 to 49 15 1 are assigned to user processes or applications. These processes are mainly applications that some users choose to install, rather than common programs that are assigned recognizable ports. When these ports are not occupied by server resources, clients can dynamically select them as source ports.

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