A cigarette is a small box of tobacco leaf cut into thin pieces and rolled into cigarettes with tissue paper. One end of the cigarette is ignited, causing the cigarette to smolder and allowing smoke to be drawn in from the other end, which is held in or in the mouth; in some cases, a cigarette holder may also be used. Most modern cigarettes are filtered and contain recycled tobacco and other additives.

The commonly used term cigarette refers to cigarette, but other substances similar to substances can also be applied to marijuana and other marijuana. The difference between cigarettes and cigars lies in their smaller size, using processed tobacco leaves and usually white paper packaging, although other colors and flavors can also be used. Cigars usually consist entirely of whole leaf tobacco.

Smoking rates vary widely around the world and have changed significantly since the first widespread use of cigarettes in the mid-19th century. In developed countries, the smoking rate tends to be stable or decline over time, while in developing countries, the smoking rate continues to rise.

Cigarette has a serious health risk, more common than other tobacco products. Nicotine, the main psychoactive chemical in tobacco and cigarettes, is addictive. About half of smokers die of tobacco related diseases, losing an average of 14 years of life. The use of cigarettes by pregnant women has also led to birth defects, including low weight, fetal malformations and premature birth. Secondhand smoke in cigarettes has proved harmful to bystanders, leading to legislation banning smoking in many workplaces and public places. Cigarette smoke contains more than 4000 compounds, including nicotine, carbon monoxide, acrolein and other harmful substances. More than 50 of them are carcinogenic. Cigarettes often cause fires that kill private homes, prompting the European Union and the United States to ban cigarettes that do not meet fire standards from 2011.