There are many species of tobacco, which are all encompassed by the plant genus Nicotiana. The word nicotiana (as well as nicotine) was named in honor of Jean Nicot, French ambassador to Portugal, who in 1559 sent it as a medicine to the court of Catherine de Medici.
Because of the addictive properties of nicotine, tolerance and dependence develop. Absorption quantity, frequency, and speed of tobacco consumption are believed to be directly related to biological strength of nicotine dependence, addiction, and tolerance. The usage of tobacco is an activity that is practiced by some 1.1 billion people, and up to 1/3 of the adult population. The World Health Organization reports it to be the leading preventable cause of death worldwide and estimates that it currently causes 5.4 million deaths per year. Rates of smoking have leveled off or declined in developed countries, however they continue to rise in developing countries.
Tobacco is cultivated similar to other agricultural products. Seeds are sown in cold frames or hotbeds to prevent attacks from insects, and then transplanted into the fields. Tobacco is an annual crop, which is usually harvested in a large single-piece farm equipment. After harvest, tobacco is stored to allow for curing, which allow for the slow oxidation and degradation of carotenoids. This allows for the agricultural product to take on properties that are usually attributed to the "smoothness" of the smoke. Following this, tobacco is packed into its various forms of consumption which include smoking, chewing, sniffing, and so on.