The initial parallel port was introduced on the IBM PC in 1981. It was designed to be compatible with the Centronics parallel standard and mostly used for connecting printers to desktop computers. It is has a 15 pin connector and allowed for a 6 foot cable between the computer and the printer.

More than ten years later (March 1994) the IEEE 1284, bi-directional parallel printer interface was introducted. The main advantages of the new interface are: bidirectional communications, protection from data loss, 10 to 20 times faster data transfer rates and a longer 10 foot cable.

ECP (Extended Capability Port) and EPP (Enhanced Parallel Port) are both implementations of the parallel standard, they both offer faster data transfer (up to 2Mb/sec).

Two to three years ago the laptop manufacturers started adding these new ports to their laptops. So, if you have an older laptops and for some reason (some peripherals might require one) you can add one through either the USB port or the PCMCIA ports.

A USB to IEEE 1284 parallel printer adapter (cable) can be purchased for around $20. You can view one from Tripp-Lite. Another alternative is a USB to IEEE 1284 parallel converter. These are more expensive, as one from Quatech costs $129.

The parallel port is an older technology, so in most cases new printers include a USB Port and in some cases a Firewire interface. Eventually USB and Firewire will completely replace parallel ports.