Smoking, in its most common form, is the act of inhaling and exhaling the fumes of burning tobacco, typically from cigarettes, cigars, or pipes. This practice involves lighting one end of a tobacco product and drawing the smoke into the mouth, down the airways, and into the lungs, where it is absorbed into the bloodstream. The primary addictive substance in tobacco smoke is nicotine, which can have both stimulating and tranquilizing effects.