Named pipe
In computing, a named pipe (also FIFO for its behaviour) is an extension to the traditional pipe concept in Linux systems. A traditional pipe is "unnamed" because it exists anonymously and persists only for as long as the process is running. A named pipe is system-persistent and exists beyond the life of the process and must be "unlinked" or deleted once it is no longer being used. Processes generally attach to the named pipe (usually a file) to perform inter-process communication.
Named pipes in Linux
Instead of a conventional, unnamed, shell pipeline, a named pipeline is explicitly created using mknod or mkfifo, and two separate processes can access the pipeline by name.
For example, one can create a pipe and set up gzip to compress things piped to it
mkfifo pipe gzip -9 -c < pipe > out
in a separate process, independently, one could perform
cat file > pipe
which would then perform the compression by gzip.
