Laser hair removal works by the process of selective targeting of a specific area of the body and using a specific wavelength to absorb light into that area. It does not work on a hair by hair basis, instead it focuses a wide beam of light that treats many hairs at one time. The wavelength of light absorbed has to be sufficient enough to damage the targeted tissue area while leaving the surrounding area basically untouched. The principle behind this process is called selective photothermolysis.