Robin Williams Mac OS X Book, Jaguar Edition, The

What is a Port?

A port is a socket, a kind of receptacle, on the back or side of a computer or on the backs of peripheral devices. The port is where you connect the peripheral device. A port is very different from a regular socket like electrical sockets in the wall, in that information goes both ways through a port. A wall socket sends power in only one direction—to a device. A port sends information back and forth between the computer and the device.

There are lots of different kinds of ports, and peripherals are made to match a certain port type. For instance, you might have USB ports, to which you can only connect USB devices, such as USB printers. If you have serial ports, you’ll connect serial printers.

The cables that connect peripherals ...