Articles Parallel port
Less commonly referred to as the Centronics interface or Centronics connector after the company that originally designed it, the port was later developed by Epson. The parallel port is found on the back of IBM compatible computers and is a 25-pin (type DB-25) computer interface commonly used to connect printers to the computer; below is an example of the DB25 interface.

The interface found on the back of parallel interfaces is commonly a 36-pin male / female connector that is held in place with levers on each side of the cable.
- Additional information and help with the parallel / LPT port can be found on our parallel port help page.
The Apple Macintosh computers use SCSI as its interface, which is parallel, but a lot more flexible when compared to the parallel port used with IBM compatible computers.
Also see: Connection, LPT, Parallel, Printer definitions, Serial port
Source : ComputerHope.Com