Serial Ports

Each computer has at least two serial ports, the connectors that enable you to plug a printer or modem into the computer. The serial ports can be attached to the CPU board, or you might have to purchase them. You use these ports when attaching a modem to the system to establish a PPP or UUCP connection. PPP and UUCP actually provide wide-area network services, since they can use telephone lines as their network media.