Simply wavelength . The wavelength is the length of the ultraviolet or infrared waves from one point (say, the crest) on one wave to the same point on the next. Infrared waves are longer than ultraviolet waves - on average about a thousand times llonger. Both ultraviolet and infrared rays are part of what is called the 'electromagnetic spectrum ' - electromagnetic waves that are all the same sort of wave except for their wavelength.
--->ultraviolet radiation has a greater frequency than visible light, that is to say that it cycles
---->The only two differences are in their frequencies and wavelengths. Both Ultraviolet radiation
----->1.In terms of frequency : UV rays = 1 x 10 16 to 8 x 10 14 Hertz IR rays = 4 x 10 14 to 1 x 10 13 Hertz
2.In terms of wavelength : UV rays = 3 x 10 -8 to 4 x 10 -7 meters IR rays =8 x