When a process opens a FIFO for reading, it will block until another process opens the FIFO for writing, and vice-versa. This ensures that there is always a reader and a writer before any data transfer occurs.
block on open is mechanism in which when any process open FIFO and is forced to wait for for another process until another process also open FIFO in complementary mode.
this mechanisms ensure that both reader and writer is available to exchange data and ensure synchronization
