What does the common end mean in electronics

In electronics, a common terminal is a port in a computer program.

Definition of common end:

1. Terminology in the computer field. In network technology, the port of hub, switch and router refers to the interface connecting other network devices, especially the port in TCP protocol and the port in the logical sense.

2. It refers to the physical ports and connectors shared by multiple lines in the power line. For example, the zero line end of the integrated circuit is often shared. The USB interface of the computer can be shared by the mouse, keyboard, U disk, printer, mobile phone data cable, etc. the card reader can also be shared by a variety of memory cards.