Morse code is usually transmitted by radio as:

Continuous Wave (CW) is the standard emission mode for transmitting Morse code. Despite the confusing name 'continuous,' the actual transmission consists of turning a steady radio frequency carrier on and off to create dots (dits) and dashes (dahs). This on/off switching makes it an 'interrupted carrier.' It cannot be a continuous carrier because a continuous, unbroken signal would not convey any information—it would just be a steady, unchanging tone. It is also not a 'series of key clicks.' Key clicks are undesirable, broadband noise pulses caused by switching the carrier on and off too abruptly, which transmitters are specifically designed to filter out.