So reader Eugene E. Eckstam of Monroe, Wis., suggests that some explanation might help.
Serial ports handle data one bit at a time, like soldiers marching single-file through a turnstile.
Parallel ports handle data eight bits at a time, like soldiers on parade marching eight abreast. In general, parallel ports are faster than serial ports, but the connecting cables are limited in length. On a typical computer, the printer is usually connected to a parallel port. A serial port might be used for a joystick or an external modem. Newer machines sport USB ports, usually two.