The term 'Fax Forerunner' refers to two technologies that preceded the fax machine: Teletype and Telex. Teletype was an electromechanical device used for sending and receiving typed messages over a telephone line. It was developed in the late 19th century and was widely used in the 20th century for communication between businesses, government agencies, and individuals. Telex was a similar technology, but it used a dedicated network of terminals and modems to send and receive messages. Telex was developed in the mid-20th century and was used primarily by businesses and government agencies. Both Teletype and Telex were eventually replaced by the fax machine, which allowed for faster transmission of documents.