Wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio (1887 to 1920) before the term radio came into use.
Wireless telegraphy originated as a term to describe electrical signaling without the electric wires to connect the end points. The intent was to distinguish it from the conventional electric telegraph signaling of the day that required wire connection between the end points. The term was initially applied to a variety of competing technologies to communicate messages encoded as symbols, without wires, around the turn of the 20th century, but radio emerged as the most significant.
Wireless telegraphy rapidly came to mean Morse code transmitted with Hertzian waves (electromagnetic waves) decades before it came to be associated with the term radio. Radiotelephony by 1920s began to displace radio telegraphy for many applications and was the basis of public broadcasting. Radiotelegraphy continued to be used for point-to-point business, governmental, and military communication, and evolved into radioteletype networks. Wireless telegraphy is still used widely today by amateur radio hobbyists where it is commonly referred to as radiotelegraphy, continuous wave, or just CW.