The Electromagnetic Spectrum is made out of wavelengths that are classified by how low, high, fast, or low the wavelengths are.
Gamma rays are the first wavelength on the spectrum with the smallest wavelength and have the most energy out. Gamma rays are used to kill cancerous cells can be 1019 Hz.
The next ray on the spectrum is X-rays, X-rays are radiation rays that allow doctors to see bones and security officers so see what's in your bags at the airport up to 30 exahertz.
Ultra Violet Rays
Ultra Violet rays make up 10% of the total light. Ultra Violet rays are used for medical treatment because it can make people produce Vitamin D usually up to 400 nm.
Infrared rays extends from the nominal red edge of the visible spectrum. Infrared radiation is usually used for night vision having up to 430 THz.
Radio rays are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 GHz to as low as 3 kHz. Radio waves are use as you can tell by the name are used in radios.
Created with images by lisang22 - "Electromagnetic spectrum" • entirelysubjective - "Humanly Visible Spectrum" • NASA Goddard Photo and Video - "Cassiopeia A supernova" • lexicon10055805 - "Angelo's X-ray"