Answer: Electromagnetic waves
Explanation:-
Electromagnetic wave is defined as the wave which is associated with both electrical and magnetic component associated with them. They can travel in vacuum as well and travel with the speed of light.
Gamma rays, X-rays , visible light and radio waves are all types of electromagnetic waves and arranged in order of increasing frequencies or decreasing wavelengths.
The relationship between wavelength and frequency of the wave follows the equation:
where,
= frequency of the wave
c = speed of light
= wavelength of the wave
From the above relation, it is visible that wavelength and frequency follow inverse relation.