Electromagnetic waves differ fundamentally from either water waves or sound waves because they 1) can have various wavelengths. 2) travel from place to place instantaneously. 3) have an unchanging amplitude. 4) can travel in a vacuum.
Compared to visible light, radio waves have 1) higher frequency and longer wavelength. 2) lower frequency and longer wavelength 3) lower frequency and shorter wavelength. 4) higher frequency and shorter wavelength.