Telegraph: An electrical device used for long-distance communication by transmitting coded signals over wires. Telegraphs were instrumental in facilitating global communication before more advanced technologies emerged.
Wireless Communication: The transmission of information over long distances without the need for physical wires or cables. Examples include radio waves, Wi-Fi, and cellular networks.
Postal System: A system for sending mail from one location to another through various transportation methods. Postal systems played a vital role in global communication by facilitating the exchange of letters and packages among individuals and nations.