Parallel buses can carry more information since data bytes don't have to be split up and sent down the bus single file. But their electrical characteristics make them good only for short physical runs, less then ten feet or so. Serial buses can be run over great distances, and their speed has been improving. That is why parallel buses are preferred for inside computers, and serial buses are used for connecting computers and peripherals. Firewire and USB are serial protocols.

One of the most popular parallel buses of all time is the IEEE-488 bus, also known as the HPIB or GPIB bus. The IEEE-1284 parallel port used to connect printers to computers is known as a Centronix port. It's hard to find any printers that still support that interface.

A parallel port signify that data is transmitted broadside as opposed to serial data whereby data is sent out singly as a water brigade one of the time. Parallel port can function up to hundreds of feet not few feet. It all depends on the speed of transmission. HAT CAN BE SAID OF BOTH TYPE.

A parallel port is a port straight from the main bus system in the computer. It used to be sent on flat ribbon cable. The idea was 16 bits of information could be sent simultaneously unlike serial that as its name suggests relies on information sent Dow a wire bit by bit. Years ago parallel was much faster over short distances than serial.

Problem with parallel and reason for the short cable length was that you had to guarentee all 16 (or 32) bits of information arrived at the same time. Imagine the chaos if the 16t bit arrived after the first 15. The instruction would be screwed.