What is tobacco? Tobacco is a green plant which produces wide and huge leaves. It is mostly grown in developing countries for two main reasons. The climate is conducive and regulations are relaxed.
Most developing countries relay so heavily on foreign exchange earned from tobacco exports to balance their national income. For this reason it has earned the name golden leaf. 75% of worldwide commercial tobacco is now produced in these countries.
The actual tobacco that is used in making cigarettes is called barley tobacco. It is trans-planted from seedlings initially prepared in trays. The main sought after component in tobacco is nicotine. A poisonous substance even to the harvesters in the fields. Nicotine is naturally produced by the tobacco plant to protect itself aganist wild grazing animals in the ecosystem.
Nicotine is what cigarette companies seek after in the manufacture of cigarettes. The tobacco is harvested and dried and goes through a number of processes to produce the best grade. The best grade is what is used to make cigarettes.
There two main buyers of tobacco in the world are cigarette companies and pharmaceuticals. Pharmaceuticals use nicotine from tobacco leaves to make nicotine replacement therapy products such as nicotine chewing gum.
So the answer in the strictest sense to the question what is tobacco is tobacco is the actual plant grown to produce cigarettes. Used loosely tobacco refers to cigarettes and smokless tobacco.
In the hands of medical professionals nicotine in tobacco is gaining ground as a useful drug in certain neurological and psychiatric conditions for its therapeutic effects. The early Indians in the United States used it as a pain killer for earache and toothache though it was generally considered a poison.