Part of Marconi's famous invention - "the wireless" - which allowed people to transmit and receive messages via radio waves. Here we see the actual coherer (receiver) which Marconi used, in 1896, to describe the power of his invention. It is currently maintained at the Oxford Museum of the History of Science. Titanic used a Marconi wireless. Photo by Ozeye, online via Wikimedia Commons. Image license: CC BY-SA 3.0
Eleven years before Titanic set sail in the early spring of 1912, Guglielmo Marconi had invented a way for ships to communicate with each other and with land-based stations. He designed a transmitter to send, and a receiver to pick up, electromagnetic radio waves.
If successful, Marconi’s system would give ships something even Samuel Morse (and his Morse Code invention) could not provide: wireless telegraphy.
At first people doubted whether messages could be sent across the ocean. They thought the earth’s curvature would prevent it. But on December 12, 1901 Marconi heard the distinctive Morse Code sounds for the letter "s." (Follow the link to check out Morse Code yourself.) His receiver was in Newfoundland. His powerful transmitter was in Poldhu (Cornwall, England).
The Morse Code signal (which was first successfully transmitted in 1844, traveling a distance of about 40 miles between Washington, D.C. and Baltimore) had now traveled 1700 miles (on a radio wave) from Cornwall to Newfoundland (by way of the ionosphere). Marconi shared the 1909 Nobel Prize for Physics and the age of radio had begun.
Ships (like the Titanic) began to install Marconi Rooms. Shipboard operators were employed by Marconi’s company to transmit and receive (plus derive income from) communications for the ship’s passengers.
With its 500-mile range limitations, however, it was not possible for the Titanic’s station (the link takes you to Father Browne's photograph which is the only known picture of it) to be in constant communication with land-based Marconi stations.