International telegraphic message-transfer service consisting of a network of teleprinters.
Subscribers to a telex service can exchange textual communications and data directly with one another. Telex systems originated in Europe in the early 1930s and were widely used for several decades. The ability to conduct high-speed digital communication over regular telephone lines led to a decline in the use of telex, but it is still used as a data transmission service for applications in which high transmission speeds are not necessary or in areas where more modern data equipment is not available.