They decode them to make sense of them again. If the results are intelligible, a conversation may begin, be it written or embedded in sound or pictures. We study the collective phenomena in many forms and many ways. Some communications we call art, others science and still others we engineer with a mathematical precision to physically accomplish something. We believe that communications may be one of the representations of the human species that distinguish us in the animal kingdom as thinking beasts.
Kids play with codes as a mental exercise.
Historians tell us that codes have played a formidable part in our history. Today they are a major part of our technology. And, to paraphrase Omar Khaayam, having writ these words upon the wall I am not sure I grasp them all. I do know that the transportation of information requires economies. We are also sensitive to the speed that the package moves at.