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Telegraphy is the long-distance transmission of written messages. The word comes from the Greek words tele (far off, or at a distance) and graphein (to write). Telegraphy is used for remote communication between distant points involving coded signals. Modern-day internet traffic is a form of telegraphy, but the term is normally associated with legacy forms of telecommunications.
Communications at a distance has a surprisingly long history. From earliest times, mankind has found clever ways to send messages beyond earshot. Smoke signals and torches were used as telecommunications media, often to send news of war or instructions for military maneuvers.
The ancient Greeks used both fire and water to send telegraphic messages. The historian Herodotus wrote about “fire-signals” that were used in 480 B.C. to communicate news of war. Polybius wrote about a torch signal data encryption system in which letters of the alphabet were substituted.
Upon hearing the word telegraph, people usually picture a clerk busily tapping out a message on an electrical device in Morse code. This is electrical telegraphy. But this is only one example of a term with a broader definition. The medium for communicating the messages can be used with the term to clarify the type of telegraphy. Here is a brief list:
Other forms of telegraphy besides electrical have been used in modern times. The French had a sophisticated system of optical telegraphy from 1792–1846. It used semaphore code, and towers were placed at 20-mile intervals around the country. Before speech was used in radio, Morse code continued to be used over wireless radio signals. Telex transmissions are still in use around the world.
The internet is the latest form of telegraphy. Although the term is not in use, electronic telegraphy could be used to describe this means of remote communication.