I was reviewing a set of interview questions that are asked from a unix admin; I found a topic called "named pipe". 

I googled the topic; to some extent I have been able to understand it :- [named pipes || FIFO](http://en.wikipedia.org/wiki/Named_pipe#In_Unix)

But still I feel that I am lacking the knowledge of when to use this particular type of pipe. Are there any special situations where unnamed pipes would fail to work ?