View source for FIFO

FIFO stands for First-in First-out.  Meaning it is a queue and the first data that enters it is the first one to leave.  Think of a concrete sewer pipe that is placed on a playground and if a group of people enter one end and their direction of movement does not change the first person in will be the first person out.  That's a FIFO.  Had the pipe one end blocked the movement would have to reverse and you have a [[LIFO]] (last-in first-out).

In Unix a fifo is a named pipe.  See [[Fifo]].