Communication is vital to mankind and nature. Even animals have some kind of communication. People talk to each other when in a listening distance of few meters. More distant they have to increase the loundness of their voice or may give signals by arms, legs or behavior with their bodies. The message contents decrease significantly, only few information could be exchanged. When the partners are out of sight other systems of communication are necessary for information exchange.

The only way of transferring information from one place to other was by means of a messenger. The message was written down and has to be forwarded physically. It took more or less time to deliver the message depending on the distance to cover.

At the end of the 18th centuary technical systems were used to improve the exchange of information. Major advantage of the new systems were, the message itself must not be forwarded physically but only the contents of the message. The message was kept by the sender. Technical systems improved the handling and speed up the forward time by and by. In modern times the message arrives within seconds from any place to any place of the world.