The electric telegraph is a communication device that transmits messages over long distances using electrical signals. Invented in the early 19th century, it revolutionized communication by allowing information to be sent quickly, compared to traditional methods like mail. The system typically used a series of wires and a code, such as Morse code, to represent letters and numbers. Operators would send messages by tapping a key, which opened and closed an electrical circuit. This created a series of clicks or signals that could be interpreted at the receiving end. The electric telegraph played a crucial role in industries like railroads and news reporting, significantly impacting society.