Amateurs use a variety of voice, text, image, and data communications modes over radio.
Encryption, for example, is not generally permitted in the Amateur Radio service except for the special purpose of satellite vehicle control uplinks.
Radio telegraphy, designed for machine-to-machine communication is the direct on / off keying of a continuous wave carrier by Morse code symbols, often called amplitude-shift keying or ASK, may be considered to be an amplitude modulated mode of communications, and is rightfully considered the first digital data mode.
Although commercial telegraphy ended in the late 20th century, Morse code remains in use by amateur radio operators.
Certain procedural activities in amateur radio are also commonly referred to as 'modes', even though no one specific modulation scheme is used.