Inter Process Communication method in linux

There are 5 different IPC methods in Linux

1. Shared memory.  (Related process)
2. Memory mapped.   (Unrelated process)
3. Pipe (Related process)
4. FIFO (Unrelated process)
5. Socket (Unrelated process in two different system)

Related processes means, parent-child kind of relation. processes created by fork,vfork kind of system call.