Radio frequency waves are electromagnetic (EM) waves, similar to microwaves. They travel at the speed of light in free space (3.0×108 m/s). RF waves typically oscillate in the frequency range of 3 kHz-300 MHz, while microwaves cover the frequency range from 300 MHz to 300 GHz.
Courtesy of NASA
For more detailed information regarding the electromagnetic spectrum please visit this very informative NASA Mission: Science web site.