First communication exchange was by means of messengers, horse coaches and rider. He carries the message from one place to an other and a message could be under way for a long time.

First technical systems for communication purposes were optical systems. The frenchman Claude Chappe created a pointer system with legs for the alphabet. There was a system in France and other countries. It was the first time the message itself must not be submitted but only the contents of it. This method of communication excelerated the forwarding time significantly. The major disadvantage of optical systems was it's dependicy on bad weather and the high manpower to manage longer distance lines.

With the invention of electricity a device come into use which could write dots and dashes on a strip of paper just the same manner the electric curcit was closed by a switch. The most advantage by using electrical lines was the undependicy of weather impacts. The distance between relay stations could be extended significantly. The information to be submitted was keyed in Morse/Gerke Code and consists on a mixture of short and long defined signals forming the alphabeth, figures and punctuation.

When wireless come into use one could cover even wider distances without a wired telegraph line between the places. Ships at high seas could take part in this system and exchange messages with coaststations to be feed into landlines and reach the adressee.

Later on a typwriter was connected to the telegraph lines and one could write on his telex (typwriter like) device to some one far away. The signals were sent via 2 wires to a similar telex device.