For about 150 years, one of the fastest media for long-distance communication was the telegram, and Telex machines appeared in the 1930s to make them even faster. All was well in the world of telegraphy until the arrival of email and the Internet almost completely rendered telegraphy obsolete. There still is, however, some interest in telex and telegrams to the point that there are those who wish to see clear differences between the two.
The Telex is a system or a service of interconnected machines that were designed to automate the telegraphic process. People may see it as a primitive precursor to email and the Internet. The telegram, on the other hand, is any message that has been transmitted through the use of telegraphy. The telegram is most commonly associated with a piece of paper with a brief message that contained essential information for the recipient. A telegram was transmitted via a number of telegraphic methods including Morse code machines such as the Morse Inker. The transmission of a telegram from sender to recipient was made faster through the Telex system and its machines.
Compared to the telegram, the Telex is a more recent invention. The Telex was developed and implemented in the 1930s in Europe, the most notable example of which was when the British postal service opened its first Telex service in 1932. Almost parallel to the development of Telex in Europe was the effort by Bell Labs in the United States, called TWX, that improved on the concept through a transmission rate of 75 bps compared to the 45.5 bps of the European Telex. The telegram is an older concept that existed prior to the 1900s. Western Union's telegraph service started in April 1856.
The Telex serves to transmit a telegram as quickly as its system can provide data and provides some degree of automation to the telegraphy. Telex made use of telephone lines for transmission that is in certain ways similar to how fax machines of today communicate. The oldest Telex machines employed rotary dialing systems to communicate with one another. Telex made use of telephone dial-pulsing on local telegraph loops and is followed by Baudot teletype, a five-current-impulses-per-character system that was an alternative to the dot-and-dash style of Morse code. The telegram, the actual thing transmitted by a Telex system, functioned to simply relay a message to a recipient. The Telex system could transmit far more data in a shorter amount of time at a lower cost than other forms of telegraphy.
The concept behind the Telex was a system that automated the process of telegraphy, made it faster and made it more cost effective. In effect, Telex was more specific in that in only supported the broader concept of the telegram, with the concept of the telegram being the message itself that aimed to deliver an important message within a limited number of words.