Tobacco
Tobacco is a product prepared from the leaves of the tobacco plant by curing them. The plant is part of the genus Nicotiana and of the Solanaceae (nightshade) family. It is used as a drug, mostly by smoking, but also by using snuff or chewing tobacco. People use cigarettes, cigars, and pipe to smoke tobacco. Tobacco contains the chemical nicotine, which causes pleasure as a stimulant drug. It also causes addiction — after people start using nicotine, it is difficult to stop. Tobacco use can cause diseases, such as many types of cancer.