Snuff is a finely ground form of tobacco. Moist snuff (sometimes in a sachet) is placed between the lower lip and gum. Nicotine from the snuff is absorbed through the skin inside the mouth. Dry snuff is a powder that is taken orally or is sniffed into the nose.
Chewing tobacco typically consists of wads of loose leaf tobacco. Nicotine from the tobacco is absorbed through the skin in the mouth.
Smokeless tobacco is not considered a safe substitute for smoking cigarettes.