IQOS: It's heating Tobacco
IQOS is a system for heating tobacco. This is the main difference with a traditional cigarette: the tobacco in a cigarette is burned at temperatures above 800°C and generates smoke that contains many harmful substances.
IQOS heats tobacco sticks (HEETS) to much lower temperatures, up to 350°C, without combustion, fire, ash or smoke. However, the use of IQOS is not risk free. The aerosol contains nicotine and is therefore addictive.