Y'all are killin’ me!
LED lamps use a different light-emitting technology (light emitting diodes); they DO NOT emit a different type of light.
The "old" lamps use fluorescent light bulbs. I totally understand why no one wants to bother with a ginormous word like "fluorescent," but by failing to properly differentiate between the type of bulbs and using "LED" versus "UV" in our terminology, we risk getting lazy in our own understanding of these things, as well as spreading ignorance and misunderstanding among our clients and the general public.
If we continue to refer to fluorescent lamps as "UV" and not use "UV" when talking about LED lamps, people will get the impression that LED lamps do not emit ultraviolet light. This will compound the problems associated with the already-existing paranoia concerning UV light. People will start thinking that LED lamps don't use UV light, and that will include a lot of nail techs out there in the world who will then tell their clients they use "LED light instead of UV" and then people will start thinking there's no UV light in LED lamps ... until eventually someone gets sued!
There are so many people in this business who take proper terminology so seriously, I don't understand why so many of these same people insist on failing to apply that proper terminology here?
There are plenty of differences between LED lamps and fluorescent lamps, but ultimately, the products we use these lamps for are cured using ultraviolet light — if LED lamps didn't emit light in the UV spectrum, they wouldn't work!
Remember: different light bulbs, not different light!