Most systems have dedicated communications ports which enable |modems|, |printers| and other devices to connect to the system. These connectors do not require the addition of an expansion card in order to make use of an external device. These connectors are usually either serial or parallel. A serial port has data transmitted in serial, or bit-by-bit, fashion while parallel ports send multiple signals all at once. Modems and |mice| are typical serial devices, while printers are usually parallel.
