Instead of straight liquid nicotine, otherwise known as "freebase," Juul uses a patented formula that combines nicotine with salt. The company says the nicotine-salt combination is similar to what’s naturally found in the leaves of a tobacco plant; the end result is a stronger e-liquid that vaporizes more smoothly.
Adults who vape using batteries that heat the liquid and produce a vapor are quite different. Eliquid is a mixture of propylene glycol, vegetable glycerol, and flavoring used to soak cotton wicks, either in pre-made or build your own form, to produce vapor when heated.
Juuling is staight nicotine.