The one way communication or you might can called it the old way of communication is that the information from the resources flow only in one way, from sender to receiver, but the sender will never get a feedback from the receiver. You can see the one way communication in your daily life such as advertisement, newspaper, books, etc. For example, Stamp wants to go out to play Pokemon Go, and he wants his mom to prepare the dinner by the time he gets home. So he just left the note for his mom to prepare the dinner. You can see that Stamp only tell his mother to do something for him but Stamp will never know what is his mom gonna reply. He can only know by the time he gets home.