All electromagnetic waves travel at the same speed in a vacuum. They all travel at the speed of light:3 x 108 m/s (or 299,792,458 m/s)
Wavelength - 103 mFrequency - 104Hz
Wavelength - 10-2 mFrequency - 108Hz
Wavelength - 10-5 mFrequency - 1012Hz
Radio waves are used in radio telescopes to study far away objects in space. Radio waves are also used for RADAR, broadcasting, and communication.
Microwaves can be used for communication between mobile phones. Microwaves can also be used to heat food. Microwaves cause the water molecules in food to get warmer.
Infrared radiation is used for thermal imaging. Infrared rays are also used for cooking food in toaster ovens. IR is used to control your TV from your remote as well.