Infrared radiation lies at the frequency just below the frequencies of visible light.
Infrared radiation is termed as an electromagnetic radiation which has longer wavelength more than those which have visible light.
Infrared radiation excites vibrational modes in a molecule through which a change in the dipole moment. Infrared examines transmission and absorption of photons which are in the infrared range. Infrared radiation is used in scientific, military, law enforcement, in industrial, and medical applications.