Teletype refers to a type of communication device that allows for the transmission of typed messages over long distances. Originally developed in the early 20th century, these machines used telegraph technology to send and receive printed messages, making them essential for news agencies, businesses, and government communications. The Teletype machines operated by converting typed text into electrical signals, which were then sent through telephone lines or radio waves. At the receiving end, another machine would decode the signals and print the message on paper. This technology laid the groundwork for modern digital communication systems.