The different frequency segments are named as radio waves (3KHz-3000GHz), infrared, visible light, ultraviolet, x-rays, gamma rays and cosmic rays. Different colors of light in the vacuum propagation speed is the same, while the wavelength is different, and thus their frequencies are different, the longer the wavelength the smaller the frequency, the shorter the wavelength the larger the frequency. The band frequency range of ultraviolet light is roughly between 8 x 10^14 and 3 x 10^17 Hz, the band frequency range of visible light is 3.9 x 10^14 to 7.7 x 10^14 Hz, and the range of infrared wavelengths is roughly between 3 x 10^11 and about 4 x 10^14 Hz.
X-rays are characterized by very short wavelengths and high frequencies.
Radio waves can be categorized by wavelength into long, medium, short, microwave, and mixed waves; and by frequency into low, high, ultrahigh, and ultrahigh frequencies.
1?High frequency. That is, medium wave and short wave. Wavelength 10 ~ 3000 meters, frequency 10^5 ~ 3 × l0^7Hz, such as high-frequency quenching, smelting, welding, cutting and other induction heating equipment, high-frequency dielectric heating equipment, plastics processing, food drying equipment, radio broadcasting and communications.
2?UHF. That is, short-wave 1 ~ 10 meters, frequency 3 × 10 ^ 7 ~ 3 × l0 ^ 8Hz, such as radio communications, television signal transmission, medical electrical equipment, electrified railroads.
3?UHF. That is, microwave. Wavelength 1 ~ <0.07 meters, frequency 3 × l0^8 ~ 3 × l0^10Hz, radio positioning, navigation, radar and so on. All are sources of artificially generated electromagnetic waves.