What are red light frequencies and how are they different from infrared?Updated a year ago

Red light is visible and is most effective for use on the surface of the skin. Red light occupies the end of the visible spectrum with wavelengths of 600nm-700nm. Infrared light is invisible, and as you increase the wavelength, from red to infrared, you also increase how far the frequencies penetrate into the body. The most effective wavelengths for red light therapy and healing range from 625nm-980nm.