The telex system represented an important intermediate stage between the telegraph and modern digital data communication. According to the textbook:

• Telex machines first appeared as an evolution of telegraph technology, using telephone-like rotary dialing to connect teleprinters (teletypes)
• By 1935, message routing was the last barrier to full automation of the system
• The first wide-coverage telex network was implemented in Germany in the 1930s, used primarily for government communication
• Technical specifications: 45.5 bits per second; up to 25 telex channels could share a single long-distance telephone channel
• This made telex the least expensive method of reliable long-distance communication at the time

Telex eventually became a global business standard for transmitting documents internationally, particularly important for news agencies (like Reuters) and international trade, before being superseded by fax and then email in the late 20th century.